FreePBX 13: User Managment with AD

Hi getting error 500 when i try to login to UCP
?display=dashboard
query-1.11.1.min.js:4 POST http://XXXXXXXXXXX/ucp/index.php 500 (Internal Server Error)

version FreePBX 13.0.1RC1.9

Are you using active directory

Thanks Andrew. We were able to make a modification to get it to work.

What was the modification?