Stable Diffusion xformers Error After Update

How to fix it

Try these in order — the most common fix is first.

1. 1. Match versions

   Copy steps
   1. Activate the venv
   2. Install the torch build for your CUDA version, then the xformers release that requires that exact torch
   3. Example reported to work: torch 2.7.0 with xformers 0.0.30
   Did this fix it? Yes No

2. 2. Skip xformers

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   1. 'No module xformers. Proceeding without it.' is only a notice
   2. Remove --xformers from COMMANDLINE_ARGS or use --opt-sdp-attention
   Did this fix it? Yes No

3. 3. Start clean

   1. Delete the venv folder and relaunch to reinstall dependencies
   Did this fix it? Yes No

Symptoms

Errors importing xformers, 'Couldn't install xformers', or version mismatch messages right after updating the UI or torch.

Why it happens

• Update bumped torch but left an older xformers
• xformers built for another CUDA version
• Torch not installed yet when xformers builds

This guide also covers

• stable diffusion xformers error
• xformers not working automatic1111
• couldn't install xformers

The same problem in other apps

All not loading, error messages & connection guides →

• Midjourney Job Failed or Internal Server Error (Midjourney)

Other Stable Diffusion errors

• Stable Diffusion CUDA Out of Memory Error
• Stable Diffusion "Torch is not able to use GPU" Error
• Stable Diffusion Black Images and NaN Error
• Stable Diffusion Model Failed to Load, Exiting
• Stable Diffusion Very Slow on Mac (M1, M2, M3)
• Stable Diffusion Not Using AMD GPU (Slow, CPU Only)
• Stable Diffusion "Couldn't install torch" Error
• Stability AI API 402 Insufficient Credits Error