Not a Stack bug. This bug was caused by SOUP; I'll keep this around a while so the patch author can be informed.
Tag markup in our tag warnings is illegible, as you can probably see:
The text in those two tags is pale yellow on white and I can only barely make it out.
This is the dungeons-and-dragons tag warning. Here's a link that'll help you trigger it: https://rpg.stackexchange.com/questions/ask?tags=dungeons-and-dragons. Click/focus the tag field then click/focus something outside it
I'm sure it wasn't like this 3½ weeks ago when these tags warnings were added, so it must be a very recent breakage. I tested both tag warnings at the time and would've pointed this out if things were this broken.