mtrace output of 'moduleinstancedoesnotexist' error when deinstalling mod_hvp

[abias]

Several weeks ago, we have migrated all instances of mod_hvp with this plugin and the CLI command
sudo -u apache php admin/tool/migratehvp2h5p/cli/migrate.php --copy2cb=1 --limit=10000 --keeporiginal=0 --execute --contenttypes=<cid>

Today, we finally uninstalled mod_hvp with the CLI command
sudo -u apache php admin/cli/uninstall_plugins.php --plugins=mod_hvp --run

During the run of this command, we saw hundreds of lines of the 'moduleinstancedoesnotexist', 'error' language string which, in english, is 'The instance of this module does not exist'.

This language string seems to be only used once in the whole Moodle codebase in /lib/grade/grade_item.php.

I did not have the time to trace these messages further down to be able to say what could be triggering them. My gut feeling is that they either are caused by some broken data handling within mod_hvp. But it could also be that they are caused by the fact that tool_migratehvp2h5p forgot to cleanup grades when it migrated the mod_hvp activity instances.

You can now either close this issue as 'not a bug' or, if you think that tool_migratehvp2h5p could really be the culprit, have a deeper look.

Anyway, thanks for this great tool!