Look at the output from the following script:
/usr/local/fop2/autoconfig-users-freepbx.sh
or it can be installed in this location instead:
/etc/asterisk/fop2/autoconfig-users-freepbx.sh
The output is the list of users/passwords, permissions, etc, as seen by fop2. Check if your login attempt uses any of the listed users/passwords or if it outputs some kind of error, etc.
