Won't Install: Installation and Startup Troubleshooting

The most frustrating moment installing ComfyUI isn't a slow download — it's after installation: double-clicking .bat and the black window flashes away, or the service starts but the browser shows a blank page. When ComfyUI won't open, it's most likely stuck at one of three points — a wrong GPU environment, the service not actually running, or a problem on the browser side. This lesson covers the common errors in the installation and startup phases one by one with causes and fixes keyed to their original messages: first use the 60-second quick check to locate the stage, then match your case.

All fixes and commands come from the official troubleshooting docs, the official portable package scripts, and the official repository; the original error messages come from the official docs or public issue titles in the ComfyUI official repository. Errors during the image-generation phase (red nodes, out of VRAM) are out of scope for this lesson — go to Troubleshooting Overview.

What You'll Be Able to Do

• Determine in 60 seconds with 4 commands: which link is broken — GPU, PyTorch, or Python
• Match ComfyUI startup failures to their cases: black window flashing away, CUDA errors, missing Linux libraries — each cause and fix
• Solve three interface problems where ComfyUI won't open: 127.0.0.1:8188 unreachable, white/garbled screen, black screen crash
• Handle the desktop version failing to start: security blocking, update loops, unsupported GPUs, and find the official log file app.log
• Learn the official way to ask for help: gather six pieces of system info and the full original error before going to GitHub Issues

Your Current Predicament

• Double-click .bat, the black window flashes away without even letting you read the error — ComfyUI startup failure with zero clues
• The black window clearly scrolled a pile of logs, but the browser can't open 127.0.0.1:8188, or the interface is all black or all white
• A string of English errors (Torch not compiled with CUDA enabled?), you copy and search it, and the answers are all over the place and contradictory

When to Use This Technique

When you need to:

• Fix Installation: Windows Portable Package or Alternative Installs — stuck installation and startup problems
• Locate the issue yourself before posting for help: wrong files installed, wrong environment, service not running, or the browser's fault

And you don't want to:

• Wait for replies on a forum after every error — the 60-second quick check saves most of the back-and-forth
• Mistake "your browser needs updating" for "ComfyUI installed wrong" and reinstall for nothing

🎒 Preparation Before Starting

• Went through Installation: Windows Portable Package or Alternative Installs (getting stuck is fine — unsticking you is what this lesson is for)
• Can find the black command-line window that launches ComfyUI (portable / manual install) or the Comfy Desktop app (desktop version)
• Desktop version users: know that the ☰ menu in the top-left corner can open Desktop Settings
• A cup of water ☕

💡 Desktop version users, look here

Comfy Desktop manages the Python environment and dependencies for you; the Python / pip troubleshooting on this page is mainly for portable package and manual install users. If the desktop version won't start, first look at Group 4; for logs, jump straight to "Still Not Working?" — that's where the official app.log is located.

Core Idea

**ComfyUI is a two-layer structure: "local service + web interface." ** The black command-line window (or the instance the desktop version launches) is the service itself; the browser accessing http://127.0.0.1:8188 is just viewing its web page. So "ComfyUI won't open" splits into two questions: Is the service running? Can the browser connect? — troubleshoot by layer first, then look at the error.

Your Symptom	Which Layer It's Stuck At	Which Group
7z extraction fails, download stalls	Files aren't in place yet	Group 5
Black window flashes and closes / exits with an error	Service fails to start (drivers, PyTorch)	Groups 1 and 3
The window is there, but the To see the GUI line never appears	Service startup interrupted	Group 1
The To see the GUI line is there, but the browser won't open	Between the service and the browser	Group 2
The interface shows a white screen, garbled screen, or black screen	Frontend / browser	Group 2
The desktop version won't open, or automatically exits after an update	The desktop app itself	Group 4

Two official "cure-all" first steps. The first two quick fixes the official troubleshooting docs list for "ComfyUI won't start" are: check the minimum system requirements, and update your GPU driver to the latest version. The official portable package README also has a blunt line: if it won't start, update your NVIDIA driver. Doing these two things first eliminates the majority of installation-time errors.

The original error text is the best search term. The last few lines of the black window, or the last section in app.log, are the original text you need—match it against the H4 headings below, or copy it directly and search GitHub Issues.

First-pass troubleshooting: a 60-second quick check

Run the four commands in order (in a terminal / command line). Portable package users take note: the bundled Python is not in the system PATH, so replace python in the commands with .\python_embeded\python.exe (first cd into the ComfyUI_windows_portable folder); examples are given in the comments.

# 1. NVIDIA 显卡被识别吗？——应该看到显卡型号和驱动版本（AMD / Intel / Apple Silicon 用户跳过）
nvidia-smi

# 2. PyTorch 认得你的 GPU 吗？——应该看到 True
python -c "import torch; print(torch.cuda.is_available())"
#    Windows 便携包用户改用下面这条
#    .\python_embeded\python.exe -c "import torch; print(torch.cuda.is_available())"

# 3. 版本号（报 bug 时官方要这两项）
python -c "import torch; print(torch.__version__)"
python --version
#    便携包用户同上替换 python；官方便携包当前自带 Python 3.13 与 CUDA 13.0 版 PyTorch

You should see: command 1 prints a GPU info table; command 2 prints True; command 3 prints the PyTorch and Python version numbers.

Fix whichever command fails: if command 1 errors out or the command isn't found → driver problem (Group 3); if command 2 prints False → PyTorch environment (Group 3); both normal but the service won't start → Group 1; the service is fine but the interface won't open → Group 2.

Common issues troubleshooting

Startup failure: the program won't start (ComfyUI startup failure)

After double-clicking the .bat, the black window flashes and closes, and ComfyUI doesn't start

Cause: the startup script failed to launch ComfyUI—most commonly an outdated graphics driver or missing runtime libraries. The official docs put a note directly in run_nvidia_gpu.bat, which reads:

If you see this and ComfyUI did not start try updating your Nvidia Drivers to the latest.
If you get a c10.dll error you need to install vc redist that you can find: https://aka.ms/vc14/vc_redist.x64.exe

Fix:

1. First update the NVIDIA driver to the latest version (the official portable package README says verbatim: Update your Nvidia drivers if it doesn't start), then double-click .bat
2. If you get the c10.dll error: install the Microsoft VC++ runtime; the official link is https://aka.ms/vc14/vc_redist.x64.exe, then retry after installing
3. Check that you downloaded the right package: RTX 20 series and above must use the standard package; the cu126 package is only for GTX 10 series and older (see Group 5 "Downloaded the wrong installer")
4. Still failing: double-click run_cpu.bat and try CPU mode once—the official docs say CPU mode runs on any hardware, but it's very slow (officially marked as a last resort only; here it's used just for troubleshooting verification). If it starts, the problem is pinned down to the GPU environment—go to Group 3

You should see: after updating the driver, double-click .bat again; the black window stays open and scrolls logs, and finally To see the GUI go to: http://127.0.0.1:8188 appears.

"Torch not compiled with CUDA enabled"

Cause: PyTorch was installed as the CPU build or a build that doesn't match your graphics card—ComfyUI wants to use CUDA but this torch wasn't compiled with CUDA support. Most common among manual-install users; the full form of the same error in the official repo's issue tracker is AssertionError: Torch not compiled with CUDA enabled.

Fix:

1. First uninstall, then reinstall according to your graphics card (from the official README troubleshooting section):

pip uninstall torch
# NVIDIA 稳定版（CUDA 13.0）
pip install torch torchvision torchaudio --extra-index-url https://download.pytorch.org/whl/cu130

2. Verify (quick check, command 2): python -c "import torch; print(torch.cuda.is_available())" must print True for it to be fixed
3. Note for Intel GPU users: on Intel this error means something different—the XPU backend is unavailable and ComfyUI mistakenly treats it as a CUDA card. Do not blindly follow the CUDA reinstall steps above; first run the official check command:

python -c "import torch; print('XPU available:', hasattr(torch, 'xpu') and torch.xpu.is_available())"

If it prints False, install the XPU build of PyTorch (official original command); the official docs explicitly warn Intel users not to install the CUDA wheel:

pip install torch torchvision torchaudio --index-url https://download.pytorch.org/whl/xpu

4. Portable package users: the package ships with a matched PyTorch, so you normally won't hit this error; if you do, the environment has been modified—consider update\update_comfyui_and_python_dependencies.bat (officially marked for use only when dependencies are broken; back up the entire installation directory before running it)

"cuDNN Frontend error: No valid execution plans built"

Cause: on Blackwell-architecture (RTX 50 series) graphics cards, PyTorch's default SDPA attention may select the cuDNN backend, which has no valid execution plan for this architecture. Per the official description: when running FLUX it hits this at the first attention block in the UNet, and not a single image can be generated.

Fix:

1. Launch with the handwritten attention implementation to bypass SDPA and cuDNN (the official docs call this the reliable fix):

python main.py --use-split-cross-attention

2. Also confirm the PyTorch build: the official docs note that Blackwell requires a CUDA 12.8 or newer build; cu121 builds won't run at all on these cards—switch to a CUDA 12.8+ / cu130 build

💡 Don't take the detour

The official docs explicitly stated: disabling the cuDNN backend before startup via sitecustomize.py to call torch.backends.cuda.enable_cudnn_sdp(False)doesn't work—this flag isn't preserved when CUDA initializes. The launch argument is the reliable fix.

"libcuda.so.1: cannot open shared object file"

Cause: on Linux, PyTorch installs the NVIDIA libraries into site-packages/nvidia/, which the system doesn't search by default. The official docs group the three identical errors libcuda.so.1, libnccl.so, and libnvinfer.so.X into the same LD_LIBRARY_PATH symptom.

Fix:

1. Add the library path to the environment variable (virtual environment users, remember to replace python3.12 with your version):

export LD_LIBRARY_PATH=$VIRTUAL_ENV/lib/python3.12/site-packages/nvidia/nvjitlink/lib:$LD_LIBRARY_PATH
# conda 环境改用 $CONDA_PREFIX/lib/python3.12/site-packages/nvidia/nvjitlink/lib

2. Don't want to write the path by hand? Let Python find site-packages itself (official original command):

PYTHON_PATH=$(python -c "import site; print(site.getsitepackages()[0])")
export LD_LIBRARY_PATH=$PYTHON_PATH/nvidia/nvjitlink/lib:$LD_LIBRARY_PATH
# 可能还需要其他 NVIDIA 库目录
export LD_LIBRARY_PATH=$PYTHON_PATH/nvidia/cuda_runtime/lib:$LD_LIBRARY_PATH
export LD_LIBRARY_PATH=$PYTHON_PATH/nvidia/cublas/lib:$LD_LIBRARY_PATH

3. Want a permanent fix: append it to the virtual environment's activate script or to ~/.bashrc (the official docs give both versions)
4. Verify: python -c "import torch; print('CUDA available:', torch.cuda.is_available()); print('CUDA version:', torch.version.cuda)"

You should see: step 4 prints CUDA available: True and the CUDA version number, and then python main.py starts normally.

ComfyUI won't open: 127.0.0.1:8188, black screen and white screen

"Failed to connect to server"

Cause: The connection between the service and the browser is broken. The official Connection Issues gives four checks: firewall, ports, VPN, proxy; plus the most common fifth one — the service simply never started.

Fix:

1. First check whether the black window shows this line — To see the GUI go to: http://127.0.0.1:8188. If this line is missing, the service didn't start; go back to group 1
2. If the line is there but the browser didn't open automatically: this is not a failure — the official docs say it usually opens automatically; if it doesn't, open your browser yourself and visit http://127.0.0.1:8188
3. Retry on a different port (default 8188; the official docs suggest trying 8189 or 8190). Portable package users: edit .bat in Notepad to add the parameter (the official docs demonstrated adding a launch parameter by editing .bat):

.\python_embeded\python.exe -s ComfyUI\main.py --port 8189 --windows-standalone-build
pause

Manual install users, just run: python main.py --port 8189.

4. Go through the official checklist: allow ComfyUI through the firewall, temporarily turn off the VPN, and disable the proxy if you don't need one
5. If you enabled --listen LAN access, note: the log will show To see the GUI go to: http://0.0.0.0:8188, and other devices must access via your local machine's IP (check with Win + R → cmd → ipconfig); 127.0.0.1 means "this machine" and does not refer to your computer when used on a phone

You should see: the browser opens http://127.0.0.1:8188 (or the new port) and the node canvas appears.

Interface white screen, garbled screen, or display issues

Cause: The browser is too old. The official system requirements state: Chrome 142 and below have known issues that cause interface display problems and performance issues. There are also public white-screen reports in the GitHub issue tracker (e.g., White screen wen loading Comfyui).

Fix:

1. Upgrade Chrome to 143 or higher before opening (quoted from the official requirement)
2. Still a white screen after switching browsers: follow "Still not working?" to collect browser console errors (F12 → Console), then search GitHub Issues

You should see: after upgrading, http://127.0.0.1:8188 renders the node canvas normally.

Black screen at startup or immediate crash (ComfyUI black screen)

Cause: The official docs group "startup crash, black screen, load failure" into the same "ComfyUI Won't Start" symptom, with only two quick fixes: verify the minimum system requirements + update GPU drivers.

Fix:

1. Verify system requirements: check against the GPU requirements quick-reference table from the previous lesson and confirm your GPU is on the supported list (NVIDIA / AMD / Intel Arc / Apple Silicon); without a discrete GPU you must use CPU mode
2. Update GPU drivers (from the NVIDIA / AMD / Intel official sites — this is the official second quick fix)
3. Portable package users: double-click run_cpu.bat (manual installs add --cpu at launch) and try again: CPU mode runs on any hardware but is slow — if it starts, the problem is the GPU environment; continue checking in group 3
4. macOS users: if MPS has problems, the official docs likewise provide a CPU fallback python main.py --cpu (can be used with --force-fp16 --cpu for memory optimization)

You should see: after updating drivers (or switching to CPU mode), the service fully starts up to To see the GUI go to: http://127.0.0.1:8188 and the interface no longer black-screens.

"Frontend or Templates Package Not Updated"

Cause: You updated the ComfyUI code with git pull, but the core dependencies didn't keep up — the frontend, workflow templates, and node docs are all separate pip packages. When a dependency update fails, it also falls back to the old version, and Falling back to the default frontend. appears in the startup log.

Fix:

1. Install the missing dependencies in the ComfyUI Python environment (official solution):

pip install -r requirements.txt

2. On China-mainland networks, add the Tsinghua mirror (provided officially):

pip install -r requirements.txt -i https://pypi.tuna.tsinghua.edu.cn/simple

3. If it still fails: first run pip list to compare versions, then install each one per the version numbers in ComfyUI/requirements.txt (the official reminder: don't take it upon yourself to upgrade to the latest version):

pip install comfyui-frontend-package==<版本号>
pip install comfyui-workflow-templates==<版本号>

4. Insufficient permissions: run the command line as administrator (one of the official troubleshooting steps)

You should see: with dependencies installed, Falling back to the default frontend. no longer appears in the startup log, and the interface is fully functional.

GPU and driver issues

"CUDA error: no kernel image is available for execution on the device"

Cause: The PyTorch CUDA build has no kernels compiled for your GPU architecture — the build and the GPU don't match. Typical cases: a new GPU paired with an old build (e.g., Blackwell with cu121), or an old GPU paired with a build that's too new.

Fix:

1. Switch to the correct package / build per the official table:

GPU	What to use
RTX 20 series and above	standard package / build (CUDA 13.0)
GTX 10 series and older	cu126 package (CUDA 12.6, Python 3.12)
RTX 50 series (Blackwell)	CUDA 12.8 or newer builds (official: cu121 builds completely fail to run)

2. Portable package users: delete the wrongly downloaded package and re-download and extract per the package-selection table from the previous lesson
3. Manual install users: run pip uninstall torch, then install the matching version, and verify with python -c "import torch; print(torch.cuda.is_available())"

"HIP error: invalid device function when running ComfyUI"

Cause: The AMD GPU architecture is not in the supported list of the ROCm build in use. The official docs provide an environment-variable override specifically for "unsupported AMD GPUs".

Solution (pick one per your architecture, official commands as-is):

# RDNA2 或更旧（如 6700、6600）
HSA_OVERRIDE_GFX_VERSION=10.3.0 python main.py

# RDNA3（如 7600）
HSA_OVERRIDE_GFX_VERSION=11.0.0 python main.py

Also confirm the PyTorch source is correct — for AMD on Linux, use the ROCm stable release:

pip3 install torch torchvision torchaudio --index-url https://download.pytorch.org/whl/rocm7.2

"My GPU is not detected"

Cause: The desktop app didn't detect a GPU — outdated drivers, missing CUDA toolchain on Linux, or an install type that doesn't use a local GPU at all (the three cases listed in the official FAQ).

Fix:

1. Update the NVIDIA driver
2. Linux users: confirm the CUDA toolkit is installed
3. Confirm your install type supports GPU: Standalone and Git Clone do; Cloud connections use a remote GPU
4. Verify from the command line (an enhanced version of quick-check item 1, official command as-is):

nvidia-smi
nvidia-smi --query-gpu=driver_version --format=csv

You should see: nvidia-smi prints the GPU model and driver version; the desktop app detects and uses the GPU normally.

Comfy Desktop app issues

"The app won't start after installation"

Cause: Platform-related startup blockers — permissions, security settings, or missing libraries. The official FAQ gives four items by platform.

Fix:

1. Windows: run it once as administrator
2. macOS: if a security warning pops up, go to System Settings → Privacy & Security and click Open Anyway
3. Linux: Confirm FUSE 2 is installed sudo apt install libfuse2; on Ubuntu 24.04+ where AppArmor blocks the Electron sandbox, add --no-sandbox and retry — ⚠️ Official warning: this flag disables the Electron sandbox for every process; use it only when the sandbox fails to start
4. Go to the download page to confirm you have the latest version

You should see: after handling the platform-specific issue, the Comfy Desktop window opens and you reach the dashboard or first-time setup.

"App is damaged"

Cause: A macOS security mechanism marks the app as "damaged". This is the first item in the official macOS troubleshooting entry.

Solution: Go to System Settings → Privacy & Security and allow the app. Other official items on the same page: for performance issues, grant Full Disk Access; for crashes, check crash reports in the Console app.

"Comfy Desktop closes by itself after an update (Windows)"

Cause: A bug officially confirmed — on Windows versions 1.0.46 and earlier, if the update download did not complete, the app flashes the update screen and closes by itself, and this recurs on every launch, before self-repair can kick in. Fixed since 1.0.47.

Solution: Manually install the latest version (official recovery steps):

1. Download the latest Windows installer (or get it from the download page)
2. Run the installer directly — there is no need to uninstall the old version first
3. Launch Comfy Desktop

You should see: the app opens normally and no longer exits automatically — your installed instance, models, and settings are all still there (officially confirmed to be preserved).

"Unsupported device"

Cause: The Windows version of Comfy Desktop only supports NVIDIA CUDA GPUs — a direct quote from the official troubleshooting docs. AMD / Intel GPU users installing the Windows desktop version will run into this.

Solution: Windows users with AMD / Intel GPUs should switch to the other two official routes:

• Official portable packages: the AMD package (ComfyUI_windows_portable_amd.7z) or Intel package (ComfyUI_windows_portable_intel.7z), see the package selection table in the previous lesson
• Manual installation (install the PyTorch matching your GPU)

Download failures, getting stuck on the Maintenance page, or insufficient disk space warnings

Cause: The desktop version pulls files from GitHub / PyPI; incorrect network or mirror settings can cause it to hang, and creating a new instance also forces a disk space check.

Fix:

1. Stuck on the Maintenance page: officially recommended to check your mirror settings — in the Chinese interface you can enable Use Chinese Mirrors (Git & PyPI) in settings: Git repositories switch to gitcode.com, PyPI uses Alibaba Cloud and Tencent mirrors; the official docs say this is faster in mainland China
2. Low Disk Space is just a warning; choose Continue Anyway to proceed (or pick a different install path); Not Enough Space for Template Models blocks that template — switch to a lighter workflow or free up disk space
3. Installer failures: officially recommended to run as administrator + ensure at least 15GB of disk space; the desktop version officially requires at least 4.85GB for each independent installation

Download and extraction issues (ComfyUI won't install)

7z extraction fails or files are incomplete after extraction

Cause: Windows adds a "locked" mark to files downloaded from the internet, which causes extraction problems. The official README has a dedicated line about this: If you have trouble extracting it, right click the file -> properties -> unblock.

Fix:

1. Right-click the .7z file → Properties → check "Unblock" → OK, then extract again
2. If it still fails: switch to 7-Zip for extraction (the official docs also note that newer Windows Explorer can extract directly)

You should see: a complete ComfyUI_windows_portable folder extracted, containing run_nvidia_gpu.bat, python_embeded, and so on.

Downloaded the wrong package: got the cu126 package for a newer GPU (or vice versa)

Cause: The official releases include multiple packages by GPU; the only pair that is easy to mix up is the two NVIDIA ones. The cu126 package is only for GTX 10 series and older GPUs; the official docs emphasize in caps: DO NOT USE THIS ON NEWER 20 SERIES AND ABOVE GPUS.

Solution: Verify the filename and re-download (see the previous lesson for the full mapping table):

Your GPU	Correct filename
RTX 20 series and above	ComfyUI_windows_portable_nvidia.7z
GTX 10 series and older	ComfyUI_windows_portable_nvidia_cu126.7z
AMD	ComfyUI_windows_portable_amd.7z
Intel	ComfyUI_windows_portable_intel.7z

You should see: after extracting the new package, double-click the matching .bat, and startup no longer reports architecture-related errors.

Slow or failed downloads (mainland China network)

Cause: The installers are hosted on GitHub Releases — the official docs note that users in mainland China may need to configure a proxy for stable access to the GitHub repositories. Slow downloads are not your mistake.

Fix:

1. Configure a proxy to access GitHub (official approach)
2. Desktop version users: enable Chinese mirrors (Git via gitcode.com, PyPI via Alibaba Cloud and Tencent mirrors, see the previous item)
3. When installing dependencies manually, switch pip to the Tsinghua mirror (officially provided): pip install -r requirements.txt -i https://pypi.tuna.tsinghua.edu.cn/simple
4. Only get packages from official channels: GitHub Releases and comfy.org/download

Still not working?

Collect evidence before asking. The official bug report template requires six pieces of system information — gather them first:

Information item	How to get it
Operating system	Windows: systeminfo | findstr /C:"OS Name" /C:"OS Version"; macOS/Linux: uname -a
ComfyUI Version	UI Settings → About page
Python Version	python --version
PyTorch Version	python -c "import torch; print(f'PyTorch: {torch.__version__}')"
GPU Model and Driver	Windows: wmic path win32_VideoController get name; Linux: lspci | grep VGA; Driver Version nvidia-smi --query-gpu=driver_version --format=csv
Installation Method	Desktop / Portable / Manual / comfy-cli

Add three more things: the console full original error text, browser console errors (F12 → Console), and the workflow .json that reproduces the issue along with a list of custom nodes.

Desktop users should look for the logs first. Comfy Desktop writes rolling logs app.log, and the quickest way in is Desktop Settings → Logs → Diagnostics → Open logs folder (open Settings via the ☰ menu). Default locations:

Platform	Log Folder
Windows	%APPDATA%\Comfy Desktop\logs
macOS	~/Library/Logs/Comfy Desktop
Linux	~/.config/Comfy Desktop/logs

Check app.log (older sessions are in the timestamped app.log_*.log). To see the output of the ComfyUI process itself, open the instance's Manage panel and use the Terminal tab.

Where to ask (official channels at a glance):

Channel	What to ask where
ComfyUI GitHub Issues	ComfyUI core issues
Comfy-Desktop Issues	desktop issues
ComfyUI_frontend Issues	frontend issues
Custom node authors	custom node issues (official guidance: contact the specific node's developer)
Official Forum / Discord / r/comfyui	community help

💡 Three things the officials recommend before asking

First search GitHub Issues and the forum to confirm it isn't a known issue; run the default workflow once to rule out workflow factors; if you installed with comfy-cli, run comfy node update all first. For troubleshooting errors during the generation stage (custom nodes, model loading, VRAM), start from Troubleshooting Overview.

Checkpoint ✅

• 60-second quick check: I've run all four commands and know which one is off
• When the black window flashes and closes, I know the order: update the graphics driver first → if it reports c10.dll, install the VC++ runtime → verify the right package was downloaded
• When 127.0.0.1:8188 won't open, I first confirm whether the To see the GUI line appears in the black window, then check the firewall / VPN / switch ports
• When the UI shows a white or garbled screen, my first instinct is to check the Chrome version (143 or higher)
• When asking a question, I include all six system info items + the full original error text + app.log (desktop version)

Lesson Summary

✅ When ComfyUI won't open, layer the diagnosis: are all files installed (Group 5) → does the service start (Groups 1 and 3) → can the browser connect (Group 2) → is the desktop version itself OK (Group 4).

✅ Two official cure-alls: verify system requirements + update the GPU driver — do these two things first before digging deeper.

✅ How to ask: six system info items + the original error text + logs, and go to the corresponding official GitHub repo or community.

Key signals recap:

Signal	Which layer	First step
Black window flashes and closes	Startup	Update the graphics driver; c10.dll → install the VC++ runtime
Torch not compiled with CUDA enabled	PyTorch environment	Uninstall torch and reinstall per your GPU
To see the GUI line present but won't open	Service ↔ Browser	Visit the URL manually; check firewall / VPN / switch ports
White or garbled screen	Browser	Upgrade Chrome to 143+
App is damaged	macOS security	Allow it in Privacy & Security
Maintenance page stuck	Network	Check mirror settings / switch to a Chinese mirror

Next Lesson Preview

Now that the environment is stable, the next step is Where to Put Models: The models Directory and extra_model_paths Explained.

You will learn:

• The full structure of the models directory and what goes in each subdirectory
• How checkpoints, VAEs, and LoRAs each find their place
• Sharing models across multiple installations with extra_model_paths.yaml

If you want to generate images right away, once your models are in place head to Your First Generation.

Related Tutorials

• Troubleshooting Overview: Start Here When Something Goes Wrong (60-second rapid check)
• Out of VRAM and Stuttering: Systematic Fixes for OOM
• Where to put models: the models directory and extra_model_paths explained