Blank Email template while rendering

Your software
My Mautic version is: 4.3.1
My PHP version is: 7.4.28
My Database type and version is: 7.4.28

Your problem
My problem is:
I have created an email template… But while previewing it on browser, i got a blank screen…
Can anyone please figure out what could be causing that issue?
Paparika → This one is working but the images are referring to instead of
Is there something misconfigured?

These errors are showing in the log:
mautic.WARNING: PHP Warning - getmypid() has been disabled for security reasons

Steps I have tried to fix the problem:
Cleared Cache, Cloudflare, restart server.