Fatal crash on exiting VR preview

  1. Create new VR Template
  2. Include ScreenPosition Node in Material ( For Stereoscopic footage )
  3. Use Media Texture in the same Material ( The stereo footage )
  4. Enter and Exit VR Preview
  5. 50% change to crash without Log. No UE4 Crash info or any hint on what may have caused the problem.

Really stops our development process because it even kills any unsaved changes immediately.
Log folders do not contain any info explaining the crash.

Addon: I build the project, it also crashes a lot even with no vr.

I isolated all elements and it seems to be the combination of a video with the screenposition node…

Hey ,

Can you provide me with your crash logs, your ‘dxdiag’, and your updated steps along with some screenshots so I can reproduce and log this report internally?

Let me know if you have further questions.


OK, tested on other PC’s still crashes.
The Log file is dated right on the minute of crashing.
Last entry is - freeing texture set.

[Second Computer][4]

So I found the below warnings within your log file, and even though it does not provide the crash information it can give you some direction on things to pay attention to and fix.

Warning: (Node SceneTexture) GBuffer scene textures not available with forward shading. If you are working with the Forward Renderer, you cannot use the SceneTexture lookups from the GBuffer.

LogCrashTracker: Crashtracker disabled due to settings.

This is probably the reason you are not getting the crash information as the crash tracker has been disabled for your project.

LogUObjectGlobals: Warning: Failed to find object ‘Class None.’

You have got an empty reference somewhere which could cause a number of issues to occur if you depend on that class at any point.

LogWmfMedia:Warning: Possible loss of audio quality in stream 0 due to sample rate != 44100 Hz

Just a simple warning that your audio device is set up to output 48 KHz and your media file is at 44100 Hz.

I would like for you to clarify if you can reproduce this in solely a VR project, or it can be reproduced in a new blank non VR project?

Thank you,

I created an empty non vr level.

I managed to narrow it down to the VR Preview or any vr mode even in standalone. It didnt matter if Forward Renderer was enabled or not. It just happens inside VR Mode - its easily recreated when i press alt+p to open and alt+p again to close the preview inside the editor.
The shader works without errors in runtime.


Bonus information:

This trick does not work in 4.14 ( every eye gets both textures) and therefore I dont have any crashes.

And it only works if the material is set to TRANSLUCENT

! I managed to get the shader work in 4.14 - so the exact same process and maps and testings and it does not crash!

Now we have to find out what makes 4.15 crash.

Hello ,

Could you provide an example project that reproduce this crash so that I could take a closer look?

Hello ,

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.