I haven't tested myself myself but this could be related to the performance issue we've detected in MDLSITE-6114 and MDLSITE-6129. If the ZIP is too big with too many files, the in-built ZIP does not cope with such time in a reasonable time.
Re: Installing custom activity module plugin stops on validating plugin
by David Mudrák -
Number of replies: 1
In reply to David Mudrák
Re: Installing custom activity module plugin stops on validating plugin
by David Mudrák -
If this is the case, then the workaround is to extract the plugin locally and upload the extracted file to Moodle manually.
See https://docs.moodle.org/en/Installing_plugins#Installing_manually_at_the_server