Gear VR Crashes in 4.12 due to particle bug

This project used to run on Gear VR in UE4.11. However running it on an S7 in Gear VR it crashes and gives me this error in the log. After deleting the particle systems from the level it will run. Please fix or tell me how to fix :slight_smile:

Log Error:

06-23 23:13:15.356  8946  8973 D UE4   : [2016.06.24-06.13.15:366][-6889872]Assertion failed: Assertion failed: IsInGameThread() [File:D:\Build\++UE4+Release-4.12+Compile\Sync\Engine\Source\Runtime\Engine\Private\Particles\ParticleComponents.cpp] [Line: 6385]

Hello BarrettMeeker,

I have a few questions for you that will help narrow down what issue it is that you are experiencing.

Quick questions:

  1. Can you reproduce this issue in a clean project?
  2. If so, could you provide a detailed list of steps to reproduce this issue on our end?
  3. The full logs from the device when the device crashes?
  4. Could you provide screen shots of any blueprints that may be involved with this issue?

Do you have any particles in your scene with instance parameters? We ran into the same crash on PC and it sounds like the same issue as https://answers.unrealengine.com/questions/434854/packaged-build-crashing-when-activating-particle-s.html .

Temporarily fixed it by removing the instance parameters of all the particles on the map, obviously this isn’t ideal but better than not working at all.

I haven’t been able to narrow it down completely but I have been able to recreate the crash by taking one of my blueprint particle systems and putting it into a new project. I haven’t had the time to step through each recreation set especially as it’s a fairly painful process building then pushing to gear VR each time. I can email you my blueprint particle system that will cause the crash I’d rather not upload it here. Let me know what email to send it to thanks!

Hello BarrettMeeker,

As asked by johnmcb, there is a known issue that calls the same function listed in the error in your original post. Are you using any particles in your scene with instance parameters?

Yes I am, I was able to make a new particle system that used an instance parameter for rate and that worked though but maybe it’s an error that only happens if you have a certain number or type of instance parameters? On the particle system that crashes it I have 5 instance parameters. Sounds like it might be the same error though.

Hello BarrettMeeker,

This appears to be the same issue (UE-32147) I will be marking this issue has resolved for now. Please feel free to update this thread with any additional information that you may have. Please visit the link below for future updates. I will be sure to bump the community interest for this issue.

Link: Packaged Build crashing when activating particle system with instanced parameters - FX - Epic Developer Community Forums

Make it a great day