Tmp directory permissions after restore of nextcloudpi

Hello everybody!

I switched nextcloudpi to buster by installing the new image to the SD-card on my Pi3 and restoring nextcloudpi afterwards. (Failed a couple of times since I thought that “include data” would not be necessary to restore a working nextcloud instance without any photos etc. but only the database)

Anyway, the restore worked except that I cannot upload any files anymore. The error message I get is:

{"reqId":"XXaZ57R8Z3Nr9YK1DVDMDwAAAMc","level":3,"time":"2019-09-09T18:28:55+00:00","remoteAddr":"192.168.178.85","user":"sven","app":"PHP","method":"PUT","url":"/remote.php/dav/uploads/sven/9f4f3056829d09e0e00810594ccd03a1/0000000000000000-0000000010239999","message":"**fread(): Unable to create temporary file, Check permissions in temporary files directory**. at /var/www/nextcloud/3rdparty/icewind/streams/src/Wrapper.php#91","userAgent":"Mozilla/5.0 (Android) Nextcloud-android/3.7.2","version":"16.0.4.1","id":"5d7699e87df57"}

php.ini sets the tmp-folder to:
/media/USBdrive/ncdata/tmp

I ran the “fix permissions” in ncp-web already. Checked the permissions on the folder and they seem to be ok as well:

drwxr-xr-x 1 www-data www-data

What else could I check?

Sven

Seems like I am not the only one: Cannot upload files, error "expected filesize 5160954 got 8192" appears

Does nobody have an idea what else to check and why this issue comes up after the restore in the first place?

I’ve restored multple times without doing much more than checking permissions, this issue looks loike somthing php related

I have the same problem, after restoring to the same hardware.