I’m having exactly the same problem. I have been having this issue for a while and have finally given up. I encrypted my files and keep getting the “you are already signed in with this password” error message. I recently changed the password to see if this would have any effect, but nothing.
Have tried both the new and old password, and the new password gives me the “you are already signed in” error message, the old password says “wrong password”.
I am trying to open the files on the original computer on which they were encrypted. I was the one who encrypted them, and I am the one trying to open them. They were not sent to me.
Axcrypt needs to acknowledge that this is a problem with their software and fix it accordingly.