We have two Windows Server 2012 R2 domain controllers that have been running on VMware 6.5 for several months with no issues. They have started to go offline i.e. no network connection, cannot authenticate users, etc. In VMware console VMware tools shows as not running. As soon as we open a console to the servers the VMware tools start and the network comes back. The System event log shows several unusual events such as the system in entering sleep, the system has returned from a low power state, the VMware CAF management agent service entered the stopped state. Has anybody seen anything like this before? I was going to remove and reinstall VMware tools but was concerned this might have an effect on the DC's.