The website implodes

I updated this website to PHP 8.0.13 and WordPress 6.3.1, and it fell over with “There Has Been a Critical Error on Your Website”. Rolling back to WordPress 6.1.3 did not help.

Debug

In wp-config.php, I changed (temporarily):

to:

That sees logging in debug.log in directory wp-content.

Diagnose

The log reported:

The documentation for implode explained that the following legacy signature had been removed as of PHP 8.0.0:

The valid signature swapped the arguments:

Fix

Line 71 of crayon_util.class.php was not the only instance of implode still using the legacy signature. A search of the code identified another instance. Swapping the order of the arguments fixed the problem.