In cPanel users with SSH access may sometimes get below error on running commands. This happens because of “Shell Fork bomb Protection” which prevent users with terminal access (ssh/telnet) from using up the server’s resources. It’s for crash protection of server by users.

-bash: fork: Resource temporarily unavailable

To solve this problem you can simply disable the Shell fork bomb protection

Login into WHM >> Security >> Security Center >> Shell Fork Bomb Protection >> Disable Protection