FreePBX 2.11 changed the parking lot module from the one most everyone has installed right now, and not sure if its commercial or not. You will probably need to alter the autoconfiguration script so it outputs the correct parking lot config based on the new schema. Be sure you have fop2admin 1.2.13 that was updated, and post the output for the park button from the command:
/usr/local/fop2/autoconfig-buttons-freepbx.sh
Or please contact us via the live help if you can provide access to your server so we can check the database settings for the park module in 2.11 an adapt fop2admin or output from the autoconf scripts.
