Summary
Engine Version:
Unreal Engine 5.5.4 (Launcher build)
Operating System:
Windows 11
Summary:
Creating a Landscape with World Partition Region Size set to 4 consistently crashes the editor with an assertion in LandscapeEditLayers.cpp.
Crash:
Assertion failed:
Info.DestPosition.X + Info.Size.X <= DestSize.X
File:
Runtime/Landscape/Private/LandscapeEditLayers.cpp
Line: 2121
Reproduction Steps:
- Create a new Blank project.
- Open or create an Open World level.
- Open Landscape Mode.
- Use:
- Section Size: 63 Quads
- Sections Per Component: 2x2
- Components: 8x8 (also reproduced with 48x48)
- World Partition Grid Size: 8
- World Partition Region Size: 4
- Press Create.
Result:
Editor crashes immediately with the assertion above.
Expected Result:
Landscape should be created successfully.
Additional Testing:
- Reproduced in completely new blank projects.
- Reproduced with different landscape sizes.
- Edit Layers enabled and disabled.
- DX11 tested.
- Clean reinstall of UE 5.5.4.
- Deleted AppData Unreal folders and DerivedDataCache.
- Crash still occurs.
Changing ONLY the World Partition Region Size:
- Region Size = 4 → crashes every time.
- Region Size = 5 → works.
- Region Size = 8 → works.
The issue appears to be specifically related to Region Size = 4.
What Type of Bug are you experiencing?
World Creation Tools
Steps to Reproduce
It happened after using epic launcher installling version 5.5.4 and then new 5.6 and going back to 5.5.4. At least that’s my assumption, as there were no other changes to my computer between it working or not.
Expected Result
Crash of the engine every single time, after trying to create landscape with World Partition Region Size 4, no matter what the combination settings are.
Observed Result
The engine crashes, every time I create landscape with region size 4, no matter what I put in other sections landscape creation.
Affects Versions
5.5
Platform(s)
Windows
For crash reports, include your callstack
LoginId:ec0dd0644f47088d09b45589aacde05a
EpicAccountId:138c771e8e944da1be0f83840b9686b0
Assertion failed: Info.DestPosition.X + Info.Size.X <= DestSize.X [File:D:\build++UE5\Sync\Engine\Source\Runtime\Landscape\Private\LandscapeEditLayers.cpp] [Line: 2121]
UnrealEditor_Landscape
UnrealEditor_Landscape
UnrealEditor_RenderCore
UnrealEditor_RenderCore
UnrealEditor_Core
UnrealEditor_Core
UnrealEditor_Core
UnrealEditor_RenderCore
UnrealEditor_RenderCore
UnrealEditor_Core
UnrealEditor_Core
kernel32
ntdll
Additional Notes
I tried everything, doing clean install, deleting all data related to unreal engine setups. Nothing fixes it. Game basically crashes whenever I try to create landscape with region size 4. Changing region size fixes the issue. I didn’t have this issue before, it all worked just fine, the issue showed up, after downgrading from 5.6 to 5.5 version of unreal. There was nothing else that happened between it working and not working properly, no updates to software, no new software installed. I tried new projects, new levels, nothing changes.