PHP 7.2 Upgrade issue

Hi support,

I'm doing a live PHP7.2 upgrade test on the site in question, the upgrade itself has gone without issue, but now I'm getting a weird error plastered all over the front end of my site and I can't for the life of me figure out what's causing it, I've been through all the plugins disabling and re-enabling them one by one but nothing seems to clear the error and I wondered if you had any ideas, below is the error:

Warning: Parameter 2 to advanced_custom_search() expected to be a reference, value given in /home/roadsafetyscot/public_html/wp-includes/class-wp-hook.php on line 286

Thank you

Scott Sibson