WA Email Form Stopped Working

https://www.prolectricllc.com/contactus.php

I have had this form online for years, always worked just fine. A customer finally told me it wasn't working so I tested it and it comes back with a This page isn’t workingwww.prolectricllc.com is currently unable to handle this request.
HTTP ERROR 500

Does anyone have any ideas what is causing it?

If you add this to the top of the page it might give a better error:

<?php ini_set("display_errors",1); ?>

I have added it.
My hosting company suggested I down grade the version of PHP that I am using. Not sure if that will solve it temporarily or even what version to choose.

This was my hosting companies response:

There I see a number of errors in both your HTTP and HTTPS PHP Script Error Logs referring to a few deprecated features, and one of the errors references your contactus.php script, for example:

[03-Jan-2022 10:28:49 EST5EDT] PHP Fatal error: Uncaught Error: Call to undefined function split() in /big/dom/xprolectricllc/www/WA_ValidationToolkit/WAVT_Scripts_PHP.php:327
Stack trace:
#0 /big/dom/xprolectricllc/www/contactus.php(15): WAValidateEM('kathy@kathybank...', true, 2)
#1 {main}
thrown in /big/dom/xprolectricllc/www/WA_ValidationToolkit/WAVT_Scripts_PHP.php on line 327

So, my guess is that you will either need to downgrade the version of PHP you are running to accommodate the deprecated script language in your contact form (you are currently running PHP 7.3.3), or you will need to update the syntax in your contact form so that it can function with the current version of PHP you are running.

You do have an older version of the code. Downgrading php version to something less than php7 would probably work.

The other option is to upgrade to DataBridge v2 and re-apply the email server behavior on the page and it will be updated to a version that is compatible with php7+.