Can't make mastery pages anymore :/

when i go to make a mastery page it says "Error An unexpected error has occurred Sorry about that we've sent a report to the server. if you continue encountering this error you may want to check the support site or forum for more information."

EDIT: ok just checked and it wont let me use ANY of my mastery pages, if i try to load one it will give me the same error. :/ please help this is really annoying. DOUBLEEDIT: ok I logged in and out of the client twice and that seemed to fix the issue. I'm not sure what caused it, but it's fixed for now.