(VR) ALSO happens in survival! When you speed swim (as the first commenter discovered). You pop out of the water, sometimes a leathal height in the air, a.d the only fix is to open your desktop in dash and reenter the game. This causes causes you to fall back down.
It really is game breaking though. Seems like it should have been patched sooner.
Confirmed here. Started a few days ago, presumably with MC 1.9.0 release
Windows 10 Home
Oculus rift
Minecraft 1.9.0
For what it's worth, I don't know for sure what the siezure issue is, but it might be a problem with that "mirrored texture" setting at the bottom of the video options (I think). It's the control that turns the live 2D desktop view on and off (and it's baddly named). If it's on, about 1 out of 3 times you'll see horrible blurring trails in VR.