Resolved WHMCS Error with PHP 7.4

[isomonkpiss]

Hello, i have an issue with WHMCS and PHP 7.4 (only)

Server Error​

503

Service Temporarily Unavailable​

The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later.

Logs:
AH01067: Failed to read FastCGI header
(104)Connection reset by peer: AH01075: Error dispatching request to :

With 7.3 it is working fine.

I m sure there are no Capacity Problems.
WHMCS says that it is an Issue by Plesk.
I checked fresh new Installation on another Server and i got the same Issue.

Can someone confirm the same issue on 7.4?

 

[burnley]

You haven't provided enough useful information I'm afraid. But did you make sure all WHMCS system requirements for *your* version are met after switching the handler to 7.4? See System Requirements - WHMCS Documentation

 

[isomonkpiss]

I found the Solution. Ioncube Loader needs to be upgraded to the last Version