Okay. We can fix this.
If you reset the password to the same thing, it blanks the field, so make sure you reset using a brand new password, at least 8 letter or numbers long.
But that might not be the issue. What I find helps is to clear your browser's cache, log out of AFF, close the browser entirely, restart the browser, and log in to AFF using the upper right hand fields only. The center field don't work and can cause the error you're getting.
Try that, and see if it works. If not, let us know and tell us exactly what happens, and we'll sort this out.