I recently updated all 3 of my paid addons and the base package. We now can't comment without getting "Nonce is invalid". I've looked and seen this error reported and have taken steps to remedy it without any luck.
I use W3 Total Cache and I've purged all caches/CDN and warmed the cache again, but the error still pops up.
My original problem was that using the user mention feature was popping up a red bar in the top right but with no error message. Now that everything is up to date it's popping the "Nonce is Invalid" when I include a user, BUT ALSO with any comment, so my site comments are down at the moment.