4.7 preview 4 crashes on opening project

Everything was fine on this project until I updated to preview 4. Now I can’t open it at all.


Unknown exception - code 00000001 (first/second chance not available)

Assertion failed: InstancedRenderData.InstanceBuffer.GetStride() == sizeof(FInstancingUserData::FInstanceStream) [File:d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\engine\private\InstancedStaticMesh.h] [Line: 493]

KERNELBASE + 37901 bytes
UE4Editor_Core + 3140052 bytes
UE4Editor_Core + 1614600 bytes
UE4Editor_Core + 1494994 bytes
UE4Editor_Engine + 3798840 bytes
UE4Editor_Engine + 4538661 bytes
UE4Editor_Renderer + 1938146 bytes
UE4Editor_Engine + 1358256 bytes
UE4Editor_Engine + 1564936 bytes
UE4Editor_Engine + 1499552 bytes
UE4Editor_Engine + 5069039 bytes
UE4Editor_Engine + 10088576 bytes
UE4Editor_UnrealEd + 6237773 bytes
UE4Editor_UnrealEd + 6405102 bytes
UE4Editor_UnrealEd + 2624356 bytes
UE4Editor_UnrealEd + 2833455 bytes
UE4Editor_UnrealEd + 2761581 bytes
UE4Editor_UnrealEd + 2678685 bytes
UE4Editor_UnrealEd + 6364224 bytes
UE4Editor_UnrealEd + 3235445 bytes
UE4Editor_UnrealEd + 3234600 bytes
UE4Editor_UnrealEd + 6585037 bytes
UE4Editor_UnrealEd + 6358174 bytes
UE4Editor!GuardedMain() + 285 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\launch\private\launch.cpp:123]
UE4Editor!GuardedMainWrapper() + 26 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\launch\private\windows\launchwindows.cpp:126]
UE4Editor!WinMain() + 249 bytes [d:\buildfarm\buildmachine_++depot+ue4-releases+4.7\engine\source\runtime\launch\private\windows\launchwindows.cpp:202]
UE4Editor!__tmainCRTStartup() + 329 bytes [f:\dd\vctools\crt\crtw32\dllstuff\crtexe.c:618]

i have this same, Foliage BUG, if you move foliage files to some another save folder, project open, witch some errors, but open,

but this bug make smth worst, you cant add new foliage, crash in editor, i fight with this 6 hours, and i em sure, its a Foliage BIG BUG !!!

Yea I just read the forums and saw a few others with the same problem and it seems to be related to instances. However, my project didn’t have any foliage in it, rather it has a blueprint that creates some instances meshes. So it’s not just foliage, it’s instances in general. Testing now to see if it’s resolved after removing that blueprint.

i get this from suport


Hi everyone,

This is a known issue and is currently under assessment. Please keep in mind that the preview builds are not guaranteed stable releases, they are still under active development. Thank you!

I have the same bug exactly. If it is instance related in the preview 4 how can I roll back to preview 3 until this is resolved? Not using a compiled engine.

better wait for fix, but forget to see fixed foliage in preview 5, meybe in the next build,


solution for run project only ! After this you LOSE all you foliage in PROJECT !,

1/move files from content folder (with all foliage meshes, from project) to another folder

2/ run project., project tell you about lost files, its normal

3/ delete all foliage in editor (shift +4)

4/ save project, close project

5/ now move all foliage files back to content folder

6/ run project, and start ADD meshes manual, becouse Foliage Tool not work in preview 4 !!!