Engine crash after creating landscape from importing height map on client travelling to the map

I encountered an engine crash every time, after importing heightmap to create a new landscape in my map, and during the client’s travelling to the modified map using C++, but the host client in the listening server works without any problem. The trace log is as follows:

Assertion failed: PIEInstanceID != INDEX_NONE [File:D:/build/++UE5/Sync/Engine/Source/Runtime/CoreUObject/Private/UObject/LazyObjectPtr.cpp] [Line: 104]

UnrealEditor_CoreUObject
UnrealEditor_CoreUObject
UnrealEditor_CoreUObject
UnrealEditor_Engine
UnrealEditor_Landscape
UnrealEditor_CoreUObject
UnrealEditor_CoreUObject
UnrealEditor_CoreUObject
UnrealEditor_CoreUObject
UnrealEditor_CoreUObject
UnrealEditor_CoreUObject
UnrealEditor_Engine
UnrealEditor_Engine
UnrealEditor_Engine
UnrealEditor_UnrealEd
UnrealEditor_UnrealEd
UnrealEditor
UnrealEditor
UnrealEditor
UnrealEditor
UnrealEditor
kernel32
ntdll

After I deleting the landscape been created, it works without any problem again. I found a workaround with switching the Default Server Map to the other map, then switch back to the modified map in Maps & Modes, but I have to do it every time the landscape is modified, so it’s quite tedious.

[Edit 1] I test my backup project in 4.26.2 to import the height map and it works without any problem BTW.

[Edit 2] After downloading the source code, then make the modification in the LazyObjectPtr.cpp at Line: 104 as follows:

Replace the original line:

check(PIEInstanceID != INDEX_NONE);

To:

if(PIEInstanceID == INDEX_NONE) {
PIEInstanceID = 1;
};

It temporarily fixed the engine crash, so I’m wondering whether when the editor starting, the previous maps specified in the Games & Modes section were reset to NONE? BTW, the heightmap was created using the TerreScruptor 2.0 software.

Just creating an empty landscape was enough to do it for me. Deleting it. Was the only solution. Without modifying engine code.

This bug seems still exists in the UE5 release version, I hope the Epic team can fix it in the next version…

Still notice they have the issue. Is there any news on it being looked at? I have no idea on how to install the source code or edit it, and changing the maps in the maps and modes didn’t seem to do anything to fix it for me.

I am also experiencing this problem. Any news?

Same. UE5. Just adding a landscape to a level, where a client travels brings Editor to the crash. No landscape = no problem. But I need landscape …

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