My users and I sometimes get the “invalid nonce” error. It is hard to replicate, but it seems to be happening more and more frequently. Now, of about 30 users, I get a report about once or twice a week of this error.I use a cache plugin called wp-optimize, but it does not resolve the problem to exclude the login page from caching. When my users get this error, I tell them to log in through wp-admin, which will work every time. Also, erasing the cache on the browser has worked. However, I am about to create a new online class with 70 new users who would not understand how to “clear cache” on their browser or “login through wp-admin”. If these users get this error, it could become a tremendous headache. I had been using ultimate member for over 2 years without this problem. All of a sudden, on 6/17, this happened for the first time. Could this be related to a recent update?
I am also desperately looking for a resolve to this issue or at least understand it better.