Modelling mode is fully corrupted this update

[Wertandrew]

Summary

I had crashes from transforming UVs, edit Triangle, Edit pivot, simplify, merge. The tool is unsafe to use currently, it constantly crashes UEFN. I don’t even need a repro, just use it and you will see. I 've had 4 crashes since yesterday all doing different things.

Please select what you are reporting on:

Unreal Editor for Fortnite

What Type of Bug are you experiencing?

UI/Tools

Steps to Reproduce

Use modelling mode and perform various actions with it. The crashes are random:
-UV transform
-Simplify action
-Edit triangles
-Merge

Expected Result

UEFN doesnt crash

Observed Result

UEFN crashes almost at 60% when using modelling mode.

Platform(s)

pc

[latunda]

Sometimes a crash can be prevented if you save results before you attempt new operation (save option In the lower right corner in the editor), but not always.

I also want these crashes fixed.

[Astrotronic]

Same here. Happening on my PC and Laptop. (I tried verifying game files but that did not resolve it)

I believe it started happening with the 34.30 release.

Are you seeing a problem where you need to select modeling mode twice to get into it? The first time trying to switch modes there is a shift in the lighting and this log output:

LogFort: [DSCT_GI_Off_C_0] TODM Condition: GI_Off = false
LogFort: [DSCT_GI_Medium_C_0] TODM Condition: GI_Medium = false
LogFort: [DSCT_Erebus_C_0] TODM Condition: Erebus = false
LogFort: [DSCT_Mobile_C_0] TODM Condition: Mobile = false
LogFort: [DSCT_PerfMode_C_0] TODM Condition: PC_PerfMode = false
LogFort: [DSA_UEFN_Ch5S1_C_0] TODM Scalability: TODM Visibility = true

As for the actual crash, It’s always a memory error similar to

Unhandled Exception: EXCEPTION_ACCESS_VIOLATION reading address 0xffffffffffffffff

Edit: New callstacks in v35:

Fatal error: [File:Z:\UEVFS\Root\Engine\Source\Runtime\CoreUObject\Private\UObject\UObjectHash.cpp] [Line: 63] 
Unidentified failure for object GizmoComponentHitTarget /Engine/Transient.EdModeInteractiveToolsContext_2:EditorInteractiveGizmoManager_0.FreeRotationSubGizmo_1.GizmoComponentHitTarget_0, hash itself may be corrupted or buggy.

[latunda]

Yes I started seeing crashes before 35.0

[Dormikon]

Until this is fixed there is a crude workaround: Don’t work too long in Modeling Mode, instead frequently exit it to Selection Mode and safe from there. Most of the time that prevents crashes at least in my project.

[Bug-Reporter]

FORT-900707 is ‘Closed’ as ‘Fixed’. The issue will be addressed in 35.20 and 42.00.