Opening folders in the outliner with large numbers of SKM/SK/Animation assets causes consistent GPU crashes and general instability on DX12.

Summary

I have a project which has a folder with 200+ SKM/SK/Animation assets.

I’ve started running into consistent and regular crashes during asset imports into this folder, as well as while opening said folder. Each crash generates the same error messages.

I have narrowed down the exact moment the editor crashes, and it’s when the small thumbnails for the assets in the outliner are being loaded/created - this is consistently be the moment the editor crashes when in DX12 mode. It happens during asset import (when it generates the thumbnails) as well as while scrolling through the folder while it’s trying to generate the thumbnails for the assets.

Variables I eliminated through testing:

  • Real time thumbnails being disabled had no effect
  • List, column, tile views all crash the editor.
  • Lore verse extension enabled/disabled had no effect
  • Lore on or off for the project itself had no effect
  • Viewport Scalability settings tested on medium low epic and observed the same effects
  • no external vram hungry programs opened simultaneously

When I switch to DX11 (using the launch flag for UEFN) all of the issues go away and I can import/browse as expected without experiencing any crashes.

I have a beefy PC so it shouldn’t really be an issue to open a folder with some assets.

Specs:
RTX 4070 12GB
64GB DDR5 6000MT/s
Ryzen 7800X3D

Please select what you are reporting on:

Unreal Editor for Fortnite

What Type of Bug are you experiencing?

Stability

Steps to Reproduce

Launch UEFN in DX12

  • Open folder with many SKM/SK/Anim assets (in my case 200+ assets was causing me not to be able to import even one asset into the folder without crashing, or view it all together without it crashing while generating thumbnails)

  • scroll down the list of assets OR import new SKM+SK+Anim files (1 or bulk import too)

  • Editor crashes

Expected Result

Folder opens correctly and doesn’t crash the editor, importing assets doesn’t crash the editor

Observed Result

Editor crashes

Platform(s)

PC

FORT-1139863 has been created and its status is ‘Unconfirmed’. This is now in a queue to be reproduced and confirmed.