I can repro
My step by step:
- Reduce
Editing grace period
to 0 to help speed up the test (optional) - Create a topic with some tags and publish
- Edit the topic to remove the tags, and save
- Open edit history and attempt to revert to re-add the tags
Expected: post revision revert would occur as normal and return the topic to its previous state where the tags were included
Actual: error message blocking revert
Though if the expectation is that you could rewind to a much earlier edit in the history that removed the tags and you wanted to revert only the tag removal and none of the later edits to the post body then this wouldn’t be expected to work as the edit history (including tag edits) is sequential. A revert in that case would be expected to add the tags back in and also remove any later edits to the post body as well.