I Can't Continue...

I have more than one user, and offered someone mutual termination in one user. They accepted it and have been released, but when I continued onto another user it came up with the option for mutual termination for the aforementioned player, who never played for the second team. I tried to click confirm or cancel, but it didn't work. So then went on holiday for a day, but upon returning from the holiday I realised it was still the same situation.

Any ideas as to how I can get rid of it?

Just manually change to the other user and than click continue. The message will disappear after a while, because it goes down the list until it is prowned. You will be still able to read and react to new messages.

The only thing I can think of that might work is to retire as manager of your second team then re-add yourself once past the problem date.