Your VPS Server is crashing intermittently with the message "System is shutting down"
When logged into your VPS through RDP, look in the bottom right corner of the virtual desktop.
If it says the "Windows Licence has expired" or anything similar to that effect, do the following:
Launch a command prompt and input the command: slmgr /rearm
After receiving a confirmation message, reboot your VPS
Once the VPS is operational again, verify the Windows License on the bottom right corner of the screen; it should display as valid for a period of 180 days or the message should not be present.