Found wrong tag — what tag??

I am enjoying Theme Check for the first time today. It helped me fix a bunch of problems in my theme. I am trying to debug an interaction between my theme and the GiveWP plugin.

I get this warning:

WARNING: Found wrong tag, remove from your style.css header.

Via Google, I see sometimes the warning actually gives the name of the wrong tag. Why does it not do it in my case? Do I have zillions of wrong tags and so it doesn’t bother to list them all? How do I know where to start? My style.css file is almost 900 lines long and it’s a bit like looking for a needle in a haystack…

Thanks!

The page I need help with: [log in to see the link]