I have the same problem. I'm using two filters: EasyPrivacy+EasyList and Fanboy's Annoyance List.
To reproduce: 1. Clear browsing data 2. Go to youtube.com 3. Search for video (ex: dogs)
Only the first 6 thumbnails appear and clicking on the "filters" button doesn't work. After a while/watching some videos, the issue seems to be resolved. This is annoying for those who clear browsing data frequently.