When testing with php 7.2.4 I get these errors when not logged in. When logged in the error goes away. It works in 7.1.16 with no issues.
Warning: sizeof(): Parameter must be an array or an object that implements Countable in webassist\mysqli\authentication.php on line 327
Warning: Cannot modify header information - headers already sent by (output started at \webassist\mysqli\authentication.php:327) in \webassist\mysqli\authentication.php on line 450