(I technically also restarted the app once again at the same time so maybe it was just the 3rd app restart)
BUT: have a clean gossa install (the folder fully deleted). then try to create a file using the button in the top right.
that’s what causing the errors for me.
BUT once i uploaded my first file, i’m wondering if it created the folders then, and from then on the new-file button worked
If you look at /home/yunohost.app/gossa right after install, the directory exists, the permissions are OK. There is no reason not to be able to create a text file in that directory.