In particular, the PHP bug affects the function of the WordPress “found_posts” filter. When called, the following warning is given:
Warning: Parameter 2 to test_call() expected to be a reference, value given
In AccessAlly 2.2.9, we have added an option in AccessAlly General Settings → Initial Setup → Additional Features → (Advanced) Always enable “found_posts” filter.
This option is only shown if the server is running PHP 7.1 or higher, which are the only versions that are affected by the PHP bug.
We recommend NOT enabling the option unless you need the post-filtering feature.
If it is, please contact server host to disable verbose error reporting.
Alternative Solution To Hide Warning
If the server host is not able to configure the PHP to hide the warning, you can install the “Turn error off” plugin to hide the warnings.