With the Linux version of VMware Server there is a bug where only the person that created a virtual machine can see its window in the VMware client program. Any other user on the server can log into the VMware server client but they will only see a black screen in the guest machine’s window. The fix is to make the .vmx file for the virtual machine executable to all users that will be viewing it with the VMware server client program:
chmod +x theGuestVMwareMachine.vmx