WHM/cPanel phpMyAdmin Internal Server Error 500 No response from subprocess (php)

Symptoms

When accessing phpMyAdmin in WHM or cPanel, the below error appears:

Description 

In WHM or cPanel, phpMyAdmin is unable to be accessed if the cPanel internal PHP RPMs are corrupted. This issue can occur for other reasons, but one of the common causes is corrupted RPMs.

Workaround

Repair cPanel's Internal RPMs.

/scripts/check_cpanel_rpms --fix

Restart the cPanel service daemon.

/scripts/restartsrv_cpsrvd --hard

Try accessing the phpMyAdmin once more to confirm if the issue has been resolved.