Question: Unable to load Server page in Whmcs.
When user logs in Whmcs and clicks on Server menu, Whmcs does not load the page and consumes much time. Such problem occurs if the HCAPI URL is not browsing.
Login in HC panel as host and go to menu My Server :: HCAPI. Click to browse the website on which API is enabled. It must be accessible from outside the server incase Whmcs is located on remote machine.
Note: If you haven’t enabled HCAPI in the panel then you must enable it to use Whmcs.
For more detail see this Article