Hello,
we’ve encountered a random crash while loading main map from save. More than 1 month ago the crash was very rare(1/30) but lately it’s became more frequent (1/10).
We use version 5.6.1 from github. The issue seems to relate to city sample mass crowd plugin. We added the plugin in some earlier version5.x but we didn’t update assets of character appearance and plugin after upgrade to 5.6
Call stack points to LODs but from call stack and logs we haven’t managed to track which asset is the culprit. I didn’t manage to find specific commit for which it has begun happening however via investigation I’ve discovered that up until one commit in our repo I’d always get 1st attached call stack (with pop up error message which I also included), and later after that commit I’d always get 2nd attached call stack. We haven’t been able to confirm with full certainty that both call stacks origin from the same problem, but it seems like so. Both happen at exactly the same moment of loading level from save, both point at LODs.
Additionaly we’ve analyzed CharacterOptions for few consecutive crashes to try to find a pattern and maybe specific asset that causes the crash but each time indexes of CharacterOptions would differ significantly.
Could You recommend what else could I try to either debug or solve this issue? Please let me know if You need any additional information.
Best regards,
Adam
Is the second callstack from ControlRig also happening to a rig for the MassCrowd character? Do you have the entities placed in the level that trigger the RenderResource deleted crash or are they spawned in using a MassSpawner? I know that things change for the samples, but I am not certain what all may have been changed. I do not think the CitySampleCrowd plugin had changes for its code, but other systems may have changed how they interact with the data. Which version were you using prior to 5.6.1? What version of CitySample did you pull the CitySampleCrowd plugin from?
-James
Hi James, thanks to reply
- Yes, second callstack is also happening for MassCrowd character
- We double checked that and they are spawned only via MassSpawner
- 5.5.1
- We dont have CitySampleCrowd plugin. We have migrated code and content from entire CitySample project (https://www.fab.com/listings/4898e707\-7855\-404b\-af0e\-a505ee690e68\). We migrated in August 2024 while on UE 5.4, from project version compatible with that engine version
Thank you for that info. It seems this may be due to something other than Mass as the LOD that is referenced in the callstacks is not one of Mass’s LOD systems. I will need to consult and possible send this over to some of my teammates who work in rendering and/or animation.
-James
There’s a fix for a loading issue that could cause callstack 2 in 5.7. You can find it on github here: https://github.com/EpicGames/UnrealEngine/commit/1710a3a5d674c2a2964d30ad2ae886b87f1d9b15
The author said it should integrate into 5.6 fairly easily. Please try that and let us know if it helps.
I suspect callstack 1 is a separate issue that’s masked by the callstack 2 crash, so if callstack 2 is fixed you may start seeing callstack 1 again. Anyway, let’s see how it goes with this fix and go from there.
Hello [mention removed] we took so time to test it since the repro was very low and indeed after the fix You’ve recommended, the crash seems to be gone! Thank You so much for the help and support.
Best regards
Adam