Steps to reproduce the issue

2 Factor Authentication must be enabled. Every now and then it goes out of sync (or something goes wrong). At that point if you enter in a two factor authentication you get the error message:

An error has occurred must match character set with 2 factor authentication

To log in you must remove any characters from 2FA and just use your user/password.

You then need to set up 2FA again. Alternately you can delete the database entry and log in without that error message.

I can show you this issue on a live client site but it is hard to deliberately replicate.

Expected result

Log in. Or an sensible error message that helps me to understand the issue. Perhaps this is a sensible error message but I don't know what it means. If it means something to someone can you assist me as it might help me to avoid the issue happening in the future.

Actual result

It looks like it logs in, but nothing is available except this error message: An error has occurred must match character set with 2 factor authentication. You then have to click "back to login" or some similar button.

System information (as much as possible)

This is a long standing issue that I have had over multiple websites. I have spoken to my host in great length about it and they have tried to assist in many ways, I can provide that information if it is helpful. In any event I find the error message unhelpful.