WHMCS 500 Error

Diagnosing WHMCS 500 errors.

While working on an addon module for WHMCS I kept getting a generic 500 error code and a blank page. I was pretty sure it was a problem in my code but there was nothing in the XAMPP error.log or the WHMCS admin dashboards so I had no way of tracking down the cause.

I managed to finally track down the cause by enabling the Display Errors option under SetupGeneral SettingsOther.