PHP Fatal error while configuring sysadmin

Just did a fresh install of latest FreePBX version 13.0.1 alpha27 and when I go to configure networking at /admin/config.php?display=sysadmin I get a blank page. Checking the http logs I see there is a Fatal error in PHP

PHP Fatal error: Function name must be a string in /var/www/html/admin/libraries/BMO/GuiHooks.class.php on line 229

I am new to the FreePBBX community so don’t know what the procedures are. Have I identified a known issue which is getting looked at or should invest time in fixing the problem myself.

Is there a public repository for the Web GUI?

go to Module admin and make sure framework is enabled and up to date.