We have upgraded the Moodle version from 3.6.2 to 3.9.1. Recently as an admin or a teacher login to the LMS, an unknown Plugin v5s39n is defective or outdated upgrade message is coming. I don't know if this one depends on which plugin. When I check in Plugin Overview I can see an unknown Plugin v5s39n, really don't know how this plugin got automatically coming to the LMS.
Anyone, please help on this as soon as possible.