“An error has been encountered. Probably Page was cached”

I’m up to date with the newest version of UM and use nexcess for hosting and caching. Caching is completely disabled but I do have exemption rules for the /login, /register and members/dashboard pages as well. When users try to register now they get the error “An error has been encountered. Probably page was cached”. Now, if they try to register again on that page (which now has the invalid_nonce and hash params in the URL) the registration will likely go through. We’ve had hundreds try to register and get this error all of a sudden so we can’t have this happen.

I’ve purged any cache that would have been there but nothing resolves this issue

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