Seen on the internet others with this issue!, but zero solutions
Only seems to happen in VR mode for me.
I dont get any logs or hints as to whats causing it. but its really causing me developer de motivation and im unable to proceed or make any changes to anything
I have the exact same problem with 4.17.1. It is pretty regular on the experience I am developing, but I haven’t been able to reproduce it yet on a clean project.
If you check the project folder of your application, under Saved there should be a Crashes folder. Have a look at the CrashContent.runtime-xml file.
In my case it seems to be linked to a DirectX call error. Here an excerpt.
<UserActivityHint>Layout=“MaterialEditor_Preview” Label=“Viewport” Content=SOverlay</UserActivityHint>
<ErrorMessage>Fatal error: [File:D:\Build++UE4+Release-4.17+Compile\Sync\Engine\Source\Runtime\Windows\D3D11RHI\Private\D3D11Util.cpp] [Line: 327] SwapChain->ResizeBuffers(1,SizeX,SizeY,RenderTargetFormat,DXGI_SWAP_CHAIN_FLAG_ALLOW_MODE_SWITCH) failed at D:\Build++UE4+Release-4.17+Compile\Sync\Engine\Source\Runtime\Windows\D3D11RHI\Private\D3D11Viewport.cpp:220 with error DXGI_ERROR_INVALID_CALL, Size=699x256 Format=DXGI_FORMAT_R10G10B10A2_UNORM(0x00000018)</ErrorMessage>
What does yours show? I have a bug report open on the AnswerHub as well (https://answers.unrealengine.com/questions/703548/regular-crash-on-4171-after-vr-preview.html).
A possible temporary workaround is to go back to 4.16.3 until this has been fixed.
Cheers,
Marco.
I have an instinct of what the issue is.
Basically Im using oculus with touch. I have been running some tests and noticed that UE4 goes back to the editor fine but the Play in VR icon is still lit like its hanging, so I kept the HMD on my head this time and noticed that the UE4 image was stuck on the Hmd until oculus home launched on the HMD and that was the exact moment that the editor crashed.
Wondering if its something to do with the handover of the HMD from ue4 to oculus home being displayed on HMD.
OH btw I did hunt for logs and “Format=DXGI_FORMAT” was also the only real error I had.
from the XML.
<ErrorMessage>Fatal error: [File:D:\Build++UE4+Release-4.17+Compile\Sync\Engine\Source\Runtime\Windows\D3D11RHI\Private\D3D11Util.cpp] [Line: 327] SwapChain->ResizeBuffers(1,SizeX,SizeY,RenderTargetFormat,DXGI_SWAP_CHAIN_FLAG_ALLOW_MODE_SWITCH) failed at D:\Build++UE4+Release-4.17+Compile\Sync\Engine\Source\Runtime\Windows\D3D11RHI\Private\D3D11Viewport.cpp:220 with error DXGI_ERROR_INVALID_CALL, Size=724x253 Format=DXGI_FORMAT_R10G10B10A2_UNORM(0x00000018)</ErrorMessage>
FROM THE LOG.
[2017.09.09-09.41.00:327][447]LogD3D11RHI: Error: SwapChain->ResizeBuffers(1,SizeX,SizeY,RenderTargetFormat,DXGI_SWAP_CHAIN_FLAG_ALLOW_MODE_SWITCH) failed
at D:\Build++UE4+Release-4.17+Compile\Sync\Engine\Source\Runtime\Windows\D3D11RHI\Private\D3D11Viewport.cpp:220
with error DXGI_ERROR_INVALID_CALL,
Size=724x253 Format=DXGI_FORMAT_R10G10B10A2_UNORM(0x00000018)
[2017.09.09-09.41.00:331][447]LogWindows: Windows GetLastError: The operation completed successfully. (0)
Same error apparently. This is exactly what I am also experiencing and I am using Touch Controllers are well. As I press the ESC key to exit the VR Preview mode, the last frame is stuck inside the HMD (which is per se pretty annoying if you ask me, it should just go black). Then I take the HMD out and as soon as I touch something in the editor (Blueprint or Material) UE4 crashes.
I tried to reproduce it on a clean project to add the evidences to my bug report but I had no luck with that yet. Not sure why. Can you reproduce it?
Cheers,
Marco.
@AlphaWolf I just found out that if the Editor window is minimized as soon as back from the VR Preview and then maximized again it doesn’t crash anymore. Not an elegant workaround, but better than the crashes!
I spoke too early. I just got a similar crash also in the packaged game. Need a fix!!!
I have rolled back the GeForce driver to version 382.53 and I don’t have any more crashes. Plus everything seems to be smoother and more stable.
EDIT: didn’t help. The editor still crashes! 
Did anyone ever find a fix for this ?
Im still suffering this problem for over a year now :(.
Its a serious Motivation killer and eventually makes me abandon doing what I’m trying to after 10 crashes with in 5 mins
I am using 4.18.3 with NVidia GeForce 384.94 driver (GTX 1070) and I haven’t had a single crash so far.
Think I may have Finally found the problem.
Disabled Asus sonic suite 2 app and some others , not crashed yet!
This is still happening with 4.22.3. On my system, I discovered that if the Epic games launcher is running in the background it will crash nearly all the time after exiting a VR level play. If I end the launcher from running in the background while UE4 engine is running I don’t get a crash. Unfortunately the launcher starts with the UE4 engine, so stopping the launcher from running after starting UE4 engine needs to be done everytime. Hope this helps
I get the crash sporadically, simply by having the VR plugins enabled. Some sessions, it will crash every exit from the editor play, then another session, crash sporadically, a different session, stable. In all cases, I haven’t touched any of the drivers or used VR. It’s the error: DXGI_ERROR_INVALID_CALL.