[insync44]

It happened when I upgraded on my Shield from 17.6 to 18.0, using the APK downloaded from Kodi site.
After a few days of unsuccessful attempts to rectify I uninstalled and went back to Krypton. Got the same problem with the Error Message "Watched Status Toolbox Error".
I disabled the addon and thus far  (one day) all is fine (video is saving last position).

Is there a way to rectify this error? I thought this add on saved my stopped position. Now how does Kodi save the position?

Thanks

[Klojum]

Got the same problem with the Error Message "Watched Status Toolbox Error". I disabled the addon and thus far  (one day) all is fine (video is saving last position).
...
Is there a way to rectify this error? I thought this add on saved my stopped position. Now how does Kodi save the position?

I don't remember Kodi by default having a 'Watched Status Toolbox'. You have probably installed some 3rd party add-on.
Contact the add-on developer(s) directly for support.

[insync44]

I think it is from one of the repos when installing different skins.

[Klojum]

Provide a debug log (wiki) so we can see some details.

[insync44]

Solved the problem. Thanks.

came from one of the Add Ons from the Rector Repo (Watched Status Toolbox) which interfered with my resume feature in Kodi. Disabling solved the problem.