SwigIT If your domain controllers are crashing and you do not believe that it is from a 3rd party application / DLL loaded into LSASS.exe then you will need to open a case so that it can be debugged. However it seems like you are saying that you are actually having High CPU going on and not a crash.
First thing I would suggest is to disconnect DC from the network and see if the CPU load goes down. If it does then you know that it is something on the network causing the issue rather than something on box. Either way you would want to troubleshoot this as a DC performance issue rather than a Crash happening.
FinIT-guy If your system is still crashing after installing the April update please open a case as we would need to troubleshoot / debug this issue.