Virtual Appliance Crash is observed in 9.1R4 OVFs. Upon restart, the Virtual Appliance may come back just fine or it may not.
From the information available this issue applies to :
9.1R4 Base Virtual Appliances running 9.1R4 Software version or later.
VMWare implementations only.
This doesn't impact :
Hardware Appliances such as PSA-7000, PSA-5000, PSA-3000 & PSA-300.