Regarding the registered issue UE-51725 - I think I have the steps to reproduce it:
Using the myself - I can quite consistently reproduce the crash by trying to look straight down using the VR helmet. This makes me suspect that when the VR helmet gyro axes are zero, 0, nil - something bad happens. That - or it is that the sensors are unable to pick up the helmet for tracking and that creates a null pointer or something. I usually see that the VR view (inside the helmet, not on the computer screen) flashes to grey - then the view starts to stutter, then it greys out entirely, then it crashes.
Thank you for the information provided, however I was unable to reproduce this issue on our end with the steps provided. A couple of things you could do to narrow down what is causing your crash would be to try and reproduce it in a completely blank project as well as make sure that you are not using any unofficial plugins.
We have not heard back from you in a few days, so we are marking this post as Resolved for tracking purposes. If you are still experiencing the issue you reported, please respond to this message with additional information and we will follow up.