[schapplm]

The backup addon seems to use the same module zipfile, but uses a different method writestr instead of write in my addon. Since my code is only a two-liner, I would prefer to adapt it.
There were already some python issues with another module on Android devices:

The Dropbox authentification mechanism seems to be broken for Android devices. LibreElec seems to be a full linux distribution, but perhaps with a reduced set of python libraries. (I don't use it so I am not sure there).

Can you please check, if you can run the zip command in a normal linux terminal on your device?
Open a terminal, enter python and in the python terminal (with ">>>" on the beginning of the line) enter

python:


import zipfile

zipfilename='/storage/emulated/0/Android/data/org.xbmc.kodi/files/.kodi/userdata/addon_data/service.watchedlist/test.zip'

dbpath='/storage/emulated/0/Android/data/org.xbmc.kodi/files/.kodi/userdata/addon_data/service.watchedlist/watchedlist.db'

with zipfile.ZipFile(zipfilename, 'w') as zf:

    zf.write(dbpath, arcname='watchedlist.db', compress_type=zipfile.ZIP_DEFLATED)

This is the code run by the watchedlist addon. Is the zip file created with this code?