RHEL 7 All commands prompt "operation not permitted"

I have RHEL 7 running on esx 5.5 server
with the vmtools 10.x loaded on it.

I am encountering this weird error that all commands I am running prompt me with "operation not permitted"

Then when I restart the VM, all things back to normal, it is randomly occurring.

Can someone please help me out?

Thank you!

Regards,
Mahaddim Shulakhantum