Hi, we are testing several scenes here using V-Ray 3.10.03 , but everything seems stable. There is a known issue
with v.4.4.0, but affects only to Mental Ray.
Did you try upgrading V-Ray to 3.10.03, or better to 3.20.02 ?
If that doesn't solve the problem, please send us the minidump
files to email@example.com. Also a simplified scene which we can use to reproduce the problem will be very helpful.