I have a landscape material with 6 blended layers. Sometimes when I landscape paint certain tiles, the editor crashes with the error:
Assertion failed: MipNum < MipInfo.Num() [File:D:\build++UE5\Sync\Engine\Source\Runtime\Landscape\Public\LandscapeEdit.h] [Line: 90]
0x00007ffee5ea6c93 UnrealEditor-Landscape.dll!UnknownFunction
0x00007ffee5dfd862 UnrealEditor-Landscape.dll!UnknownFunction
0x00007ffee5f07785 UnrealEditor-Landscape.dll!UnknownFunction
0x00007ffe72245d3e UnrealEditor-LandscapeEditor.dll!UnknownFunction
0x00007ffe72244e98 UnrealEditor-LandscapeEditor.dll!UnknownFunction
0x00007ffe721fd363 UnrealEditor-LandscapeEditor.dll!UnknownFunction
0x00007ffe7224da1d UnrealEditor-LandscapeEditor.dll!UnknownFunction
0x00007ffe721cc040 UnrealEditor-LandscapeEditor.dll!UnknownFunction
0x00007ffecb3ac840 UnrealEditor-UnrealEd.dll!UnknownFunction
0x00007ffecb3d161d UnrealEditor-UnrealEd.dll!UnknownFunction
0x00007ffecb409083 UnrealEditor-UnrealEd.dll!UnknownFunction
0x00007ffecb48081d UnrealEditor-UnrealEd.dll!UnknownFunction
0x00007ffecb9b57e3 UnrealEditor-UnrealEd.dll!UnknownFunction
0x00007ffecb37d4a2 UnrealEditor-UnrealEd.dll!UnknownFunction
0x00007ffecbfff6a6 UnrealEditor-UnrealEd.dll!UnknownFunction
0x00007ff78aa18e0b UnrealEditor.exe!UnknownFunction
0x00007ff78aa3e33c UnrealEditor.exe!UnknownFunction
0x00007ff78aa3e42a UnrealEditor.exe!UnknownFunction
0x00007ff78aa418a4 UnrealEditor.exe!UnknownFunction
0x00007ff78aa570c4 UnrealEditor.exe!UnknownFunction
0x00007ff78aa5a37a UnrealEditor.exe!UnknownFunction
0x00007fff47bc7374 KERNEL32.DLL!UnknownFunction
This only happens on certain landscape tiles and rarely happens, which makes it very hard to pinpoint the issue. Even if I delete the tile and add it back again, this doesn’t fix the problem.
The only way I’ve fixed it is to fully paint the tile in question with layer 1 (painting with layer 1 doesn’t cause a crash, only 2-6), then when the tile is filled, I can paint with the other layers without crashing. Obviously this isn’t an ideal solution, has anyone else encountered this and has a better fix?