TypeError: Argument 1 passed to str_starts_with() must be of the type string when managing domains
After updating to WHMCS v8.6.0, users of the ResellerClub registrar module may encounter a
TypeError when accessing a client's Domains tab in the admin area, when that account contains a domain transfer:
TypeError: Argument 1 passed to str_starts_with() must be of the type string, null given
endtime values returned by the ResellerClub API are null or non-numeric for this domain, when WHMCS expects to receive a timestamp.
We have created a hotfix for WHMCS 8.6.0 to resolve the error:
Switch your hosting environment to PHP 8.1.
For more information see How to Use WHMCS with PHP 8.1.