SOLVED! I did not have a copy of "uncl.tff" to delete in my fonts folder, however I found a post on a forum for another unity-based game that had similar issues and was able to use the solution they found. Here's what I had to do-
So in my case it seems that it was not that uncl.tff was corrupt and needed to be deleted but that it was not present at all. I hope that this is helpful for anyone else with this issue.
Crossbar? In the middle. — and this conveniently agrees with the “serif” version of mine.
edit: …and here’s a matching definition.