What about seafile-server-latest/seahub/requirements.txt?

[Jack_Miller]

I guess this is just a note what dependencies you’ll need for Building seahub from source.
But right below someone else mentioned the same:

Seahub "Failed to create thumbnail"

I had the same problem and I resolved it. My problem was the version of Pillow. You can see the version you need on the doc: seafile-server-latest/seahub/requirements.txt To solve this just do: Check the version: pip show Pillow Uninstall the actual version: pip uninstall Pillow Install a compatibile version: pip install Pillow==2.6.1