Light Propagation Volume enabled causes "Assertion failed: IsInRenderingThread()" crash in Development build

Summary:

Enabling LPV by adding “r.LightPropagationVolume = 1” to either the engine’s ConsoleVariables.ini or a project’s DefaultEngine.ini causes Development builds to crash when run.

Note: There are 0 error(s) and 0 warning(s) reported when building.

Note: Only Development builds crash. Shipping builds appear to run fine. The game runs fine in editor.

Repro:

  1. Launch 4.17

  2. Create a new blank project with no starter content

  3. Go to File → Save Current As and click Save to save the default map as “NewMap” in the Content folder

  4. Go to Edit → Project Settings → Maps and Modes and set NewMap to be the default Editor Startup Map and Game Default Map

  5. Close the window and exit the editor

  6. Do one of the following:

Add “r.LightPropagationVolume = 1” to the engine’s ConsoleVariables.ini file and save it

or

Add the following to the project’s DefaultEngine.ini file in the project’s Config folder and save it

[SystemSettings]

r.LightPropagationVolume = 1

  1. Restart the editor and re-open the project

  2. Check that File → Package Project → Build Configuration is set to Development

  3. Package a build by going to File → Package Project → Windows → Windows (64-bit)

  4. Select a folder location and click Select Folder

  5. The build will complete with 0 errors and 0 warnings

  6. Run the build from the selected location in Windows and it will crash with the following error:

The Game has crashed and will close

Assertion Failed: IsInRenderingThread()
[File:D:\Build++UE4+Release-4.17+Compile\Sync\Engine\Source\Runtime\Renderer\Private\PostProcess\SceneRenderTarget.cpp][Line: 2070]

Hello afelius,

Thank you for the information above, however I was unable to reproduce this issue on our end. Could you provide a sample project so that I could take a closer look?

Sure thing. What is the preferred method? If you send me a PM, I can provide a link to a test case.

Also, FYI, I’ve reverted my actual project back to 4.16 so this is no longer relevant. I started getting a lot of crashes upon compile and play in editor.

Hi Rudy, here’s a dropbox link to the project. The development build is in the WindowsNoEditor folder.

PW: Unreal_LPV

I was able to reproduce this issue on our end with the information provided. I have written up a report and I have submitted it to the developers for further consideration. I have provided a link to the public tracker. Please feel free to use the link provided for future updates.

Link: Unreal Engine Issues and Bug Tracker (UE-49205)

Make it a great day