Hi,
We recently found that on certain computers, using AutoSetup causes Unreal to crash when importing FBX files. However, since we have been unable to reproduce the issue on our side, we are not sure what is causing it.
So we want to reach out here to see if anyone has encountered a similar issue and try using this version (currently only for 5.6) to see if it resolves the problem. If it doesn’t, could you please provide the log files to us?
The log files can be found at: {Your Unreal Project}\Saved\Logs\
Thank you all.
UE 5.7 RL Auto Setup plugin crash — findings from support ticket & debugging
I opened a support ticket with Reallusion about Unreal 5.7 Auto Setup crashing when importing CC characters. Summary of what I found so far:
Environment
- Unreal Engine: 5.7.1
- Reallusion Auto Setup: 2.0 for UE 5.7 (All-in-One)
- Happens in fresh projects as well as existing ones
Initial observation
- Some characters don’t have an issue importing, some do.
- For example, I tried a working character, but changed it to have no beard or no hair, and it crashes during Auto Setup.
- These characters import just fine without the Auto Setup
Where it crashes
Unreal asserts inside RLPlugin:
Assertion failed: Pair != nullptr
TMap::FindChecked()
FRLPluginModule::AutoSetup() (RLPlugin.cpp:1227)
FRLPluginModule::SetupAll() (RLPlugin.cpp:517)
UCCFbxFactory::FactoryCreateFile() (CCFbxFactory.cpp:284)
As far as I can tell, this is not an out-of-memory crash — it is a deterministic assert from FindChecked() on a missing map key.
Debugger results
Breaking at the assert shows:
- The lookup key is the character/import name.
- The
TMap<FString, TArray<FRLConstraintStruct>> does not contain this key.
- With beard/full parts, the map is populated and the lookup succeeded.
- Having removed hair, the map is empty or missing that key, but AutoSetup still calls
FindChecked().
Support response so far
Support was able to import on their machine and suggested:
- checking export settings
- Subdivision level and RAM
However:
- I have 64 GB RAM
- The same assert happens at SubD0 and SubD2 depending on avatar
- Debugger shows this is a missing-key logic bug, not memory exhaustion
I cannot read the dll code, but my guess is that the FindChecked needs to be done with some extra guards?
Log file
For some reason im not allowed to upload links in this thread, so here is the link but broken in two (just remove the whitespace between google .com):
drive.google .com/file/d/1ZRxG2am-2pizFobSSyj9F4f3JSzYYpZf/view?usp=sharing
Let me know if i can be of any use in troubleshooting this.
small update
It might also be worth mentioning that I was able to get the failing avatars working if I exported to iClone and then use the transfer feature. So the pipeline: CC → iClone → UE. That also uses the auto plugin as far as I could tell, but it was able to import the avatars I had trouble with previously using this pipeline? Can it have something to do with that iClone skips the entire rig creation step?
It sounds like the UE 5.7 Auto Setup crash is caused by a logic issue in the plugin rather than system limits. The assert in FindChecked() fails when certain character variations (like no hair or beard) aren’t in the internal map, so the plugin tries to access a key that doesn’t exist. Using the iClone transfer workaround works because it seems to skip the rig creation step, avoiding the missing-key problem. Essentially, the crash isn’t random—it’s triggered by specific character configurations missing expected map entries.
Hi andersenjari1512,
Thank you for the information you provided.
This version of Auto Setup should resolve the issue you’re experiencing:
Please try installing this version and let us know if the problem is resolved.
Best regards,