I am attempting to obliterate a bad tag (subjective, in this case, although it was originally the chunks tag that ended up this way due to some experimentation; also note that I've since manually cleaned up the tags on each question).
When I go to the merge UI for the tag, and leave the merge target blank, I can still click "Preview Merge." This tells me that subjective will be removed from six questions, and added to none (which is exactly what I want). However, when I click "Perform Merge" I am greeted with the "Oops, something bad happened" error message screen. @Noctrine has reproduced the same behavior, so I don't think it's me.
The UX certainly implies that I can merge a tag with a blank tag to remove it from existence, and I think it's a useful feature as I've had to make a pass through bad tags two or three times now and manually get rid of them all.
Is this supposed to work the way I think? If not, it's certainly at least a bug that I'm allowed to preview a merge that will fail.
