Regardless of extensions enabled, in non-private windows, I can't post a reply (it just reloads with the text added to the url, but without actually submitting it), click on the "load more comments" buttons, or open post previews. In private windows everything functions as normal. This has been happening since updating past 1.10.867.34, I'm currently on 1.11.894.3.
Edit: deleted the cache, seems to have fixed it. Probably got messed up when restoring from a backup.