Publishing a page tree might take some time. If this is the case and you're quick enough to trigger an unpublication of the same page tree, you might get an exception because Magnolia tries to deactivate something that wasn't properly activated yet (tested with ee 5.2.7 and 5.3.2). We should check how to prevent running into this situation. e.g. introduce a kind of dependencies between asynchronously executed action (only start second when the first is indeed finished).
Approach to solve this will be quietly ignore Exception for this case, and continue activation.

Solution approach depends on MGNLACTIVATION-99.