Typical steps to reproduce:
You need to find a plugin with an old version that supports Moodle 3.3, an a more recent veresion that supports Moodle 3.3
- Install Moodle 3.3.x.
- Install Version 2.2 of https://moodle.org/plugins/pluginversions.php?plugin=qtype_pmatch
- Use the admin UI to start upgrading Moodle to 3.6.1 (or whatever the lates stable is).
- During the process, run the check to look for newer versions of installed plugins.
- Use the option to upgrade the plugins to the latest version (qtype_pmatch has Wersion 2.3 which supports Moodle 3.6, but not 3.3)
Expected result: that works, and you can continue on through the upgrade.
Acutal results: After downloading the new version of the plugin, it validates the zip, and fails because Wersion 2.3 of qtype_pmatch does not support Moodle 3.3.x. That is, the plugin upgrader is checking the version from the DB (which we are about to move away from), not the version from the code (to which we are about to upgrade).
Work-around: if you upgrade Moodle core first, then the admin UI will happily upgrade the plugin.