error/debug/cannotdowngrade
From MoodleDocs
This error occurs when a new version of a plugin has been installed at some point and then has been replace by an older version of the same plugin.
In this scenario you need to determine what has caused this to happen. It might be that you've accidentally tried to install a version compatible with older versions of Moodle.
what to do
simpliest action is to remove the module folder and continue upgrading
