Ubuntu guest virtual machine running on VMware ESXi becomes unresponsive when increasing screen resolution. The virtual machine itself has not frozen and can be shutdown gracefully via ssh.
This issue can be caused by insufficient video memory assigned to the virtual machine.
To resolve:
Shutdown the virtual machine
Edit the virtual machine properties and select Video card
Choose Specify custom settings and increase the total video memory accordingly
Click OK, power on the virtual machine and set the required resolution
