I am not using a custom landscape material. I did not change anything about the landscape. I am not using a custom brush. I did not import any alphas to use for landscape brushes.
Assertion failed: (DefaultAlphaTexture != nullptr) && DefaultAlphaTexture->Source.IsValid() [File:D:\build++UE5\Sync\Engine\Source\Editor\LandscapeEditor\Private\LandscapeEditorObject.cpp] [Line: 541]
0x00007fffa68f00c7 UnrealEditor-LandscapeEditor.dll!UnknownFunction
0x00007fffa68ce4c0 UnrealEditor-LandscapeEditor.dll!UnknownFunction
0x00007fffa6883442 UnrealEditor-LandscapeEditor.dll!UnknownFunction
0x00007fffe51c8eef UnrealEditor-UnrealEd.dll!UnknownFunction
0x00007fffe484392c UnrealEditor-UnrealEd.dll!UnknownFunction
0x00007fffcfe3c190 UnrealEditor-LevelEditor.dll!UnknownFunction
0x00007fffcfdbf8b7 UnrealEditor-LevelEditor.dll!UnknownFunction
0x00007fffedc50b21 UnrealEditor-Slate.dll!UnknownFunction
0x00007fffedd614b6 UnrealEditor-Slate.dll!UnknownFunction
0x00007fffedd65700 UnrealEditor-Slate.dll!UnknownFunction
0x00007fffedd39a64 UnrealEditor-Slate.dll!UnknownFunction
0x00007fffedde08d6 UnrealEditor-Slate.dll!UnknownFunction
0x00007fffede06a73 UnrealEditor-Slate.dll!UnknownFunction
0x00007fffedd6712c UnrealEditor-Slate.dll!UnknownFunction
0x00007fffedb9a508 UnrealEditor-Slate.dll!UnknownFunction
0x00007fffedb7ffca UnrealEditor-Slate.dll!UnknownFunction
0x00007fffedbe6863 UnrealEditor-Slate.dll!UnknownFunction
0x00007fffedbd5343 UnrealEditor-Slate.dll!UnknownFunction
0x00007fffedbcafec UnrealEditor-Slate.dll!UnknownFunction
0x00007ff82d8719a2 UnrealEditor-ApplicationCore.dll!UnknownFunction
0x00007ff82d8567d1 UnrealEditor-ApplicationCore.dll!UnknownFunction
0x00007ff82d874391 UnrealEditor-ApplicationCore.dll!UnknownFunction
0x00007ff82d84ff93 UnrealEditor-ApplicationCore.dll!UnknownFunction
0x00007ff8596ce858 USER32.dll!UnknownFunction
0x00007ff8596ce299 USER32.dll!UnknownFunction
0x00007ff82d875849 UnrealEditor-ApplicationCore.dll!UnknownFunction
0x00007ff625027332 UnrealEditor.exe!UnknownFunction
0x00007ff62504287d UnrealEditor.exe!UnknownFunction
0x00007ff62504296a UnrealEditor.exe!UnknownFunction
0x00007ff625045680 UnrealEditor.exe!UnknownFunction
0x00007ff6250571b4 UnrealEditor.exe!UnknownFunction
0x00007ff62505a516 UnrealEditor.exe!UnknownFunction
0x00007ff85a607344 KERNEL32.DLL!UnknownFunction
0x00007ff85b6826b1 ntdll.dll!UnknownFunctionCrash in runnable thread StallDetectorThread