In DB migration failure installing remote execution plugin, remote-execution was reported to be broken in 3.6 due to settings.category migrations which I would assume is caused by https://projects.theforeman.org/issues/29939. This seems to be fixed in Fixes #36003 - Migration error 'column settings.category does not exist' by stejskalleos · Pull Request #778 · theforeman/foreman_remote_execution · GitHub, but that PR is (from what I can tell) only in remote-execution 9.1, while 3.6 plugin repos only ship 9.0.
I would assume a release of remote-exection 9.1 to the 3.6 plugin repos should fix this, but maybe someone with better knowledge can take a look.
