Hey there! Do you have a large number of WordPress instances on the machine? I've seen this error before when the system is low on resources. If changing the cPanel PHP Memory Limit value in WHM >> Tweak Settings resolves this issue, that would be the cause. Can you try increasing that and seeing if that resolves the issue?
Hi
It doesn't resolve the issue:
Updating “Max cPanel process memory” from “4096” to “”.
“Max cPanel process memory” was updated.
Updating “cPanel PHP memory limit” from “512” to “4096”.
“cPanel PHP memory limit” was updated.
Processing post action for cPanel PHP memory limit:
“cPanel PHP memory limit” was updated.