Multiple users, include admin, can no longer create directories, text files. I can navigate the external storage. Not clear to me when permissions changes - was using 11.0.2 yesterday with everything working.
I suppose during the update procedure you unmounted the external storage, right?
Try to remove the external storage and attach it again (from the Admin Page) and give it another name.
It appears to have deleted all the files in the SFTP. Really bad.
And I still cannot create things there.
If things break so badly after an update, please report directly to the bugtracker. Don’t forget to use the template and to give more information about your system and corresponding logfiles: