HLOD proxy generation always crashes editor with certain mesh

A mesh from a market place package is responsible for always crashing the editor. Removing the mesh from the scene fixes the problem. The error here in particular Raw mesh is corrupt for LOD0 seems to be the problem. Any idea how to make the mesh “none corrupt” ?

[2016.12.27-17.14.19:276][404]LogHierarchicalLODUtilities: Building Proxy Mesh for Cluster LODActor_6
[2016.12.27-17.14.19:554][404]LogMaterialUtilities: Flattening material: Wall_Arch_Inst2
[2016.12.27-17.14.19:747][404]LogMaterial: Missing cached shader map for material FExportMaterialRenderer Wall_Arch_Inst2, compiling. 
[2016.12.27-17.14.20:275][404]LogMaterial: Missing cached shader map for material FExportMaterialRenderer Wall_Arch_Inst2, compiling. 
[2016.12.27-17.14.20:808][404]LogMaterialUtilities: Material flattening done. (Wall_Arch_Inst2)
[2016.12.27-17.14.20:868][404]LogMaterialUtilities: Flattening material: Stairs_Circular_Inst1
[2016.12.27-17.14.20:871][404]LogMaterial: Missing cached shader map for material FExportMaterialRenderer Stairs_Circular_Inst1, compiling. 
[2016.12.27-17.14.21:346][404]LogMaterial: Missing cached shader map for material FExportMaterialRenderer Stairs_Circular_Inst1, compiling. 
[2016.12.27-17.14.21:816][404]LogMaterialUtilities: Material flattening done. (Stairs_Circular_Inst1)
[2016.12.27-17.14.21:880][404]LogTexture:Display: Building textures: M_LOD_Wall_Arch_246_Diffuse (BGRA8)
[2016.12.27-17.14.21:989][404]LogTexture:Display: Building textures: M_LOD_Wall_Arch_246_Normal (BGRA8)
[2016.12.27-17.14.22:073][404]LogMaterial: 0.00 seconds spent updating 1 materials, 1 interfaces, 0 instances, 1 with static permutations.
[2016.12.27-17.14.22:085][404]LogStaticMesh: Building static mesh LOD_Wall_Arch_246...
[2016.12.27-17.14.22:087][404]LogMeshUtilities:Error: Raw mesh is corrupt for LOD0.
[2016.12.27-17.14.22:088][404]LogStaticMesh: Built static mesh [0.00s] /Game/LOE/Maps/HLOD/Ruins1_HLOD.LOD_Wall_Arch_246
[2016.12.27-17.14.22:097][404]LogWindows: Windows GetLastError: The operation completed successfully. (0)
[2016.12.27-17.14.22:551][404]LogCrashTracker: 


[2016.12.27-17.14.22:551][404]LogCrashTracker: 


[2016.12.27-17.14.22:551][404]LogWindows:Error: === Critical error: ===
[2016.12.27-17.14.22:551][404]LogWindows:Error: 
[2016.12.27-17.14.22:551][404]LogWindows:Error: Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:d:\build\++ue4+release-4.14+compile\sync\engine\source\runtime\core\public\Containers/Array.h] [Line: 634] 
[2016.12.27-17.14.22:551][404]LogWindows:Error: Array index out of bounds: 0 from an array of size 0
[2016.12.27-17.14.22:551][404]LogWindows:Error:

Maybe related Unreal Engine Issues and Bug Tracker (UE-37988)

The thing is, i successfully HLOD the level, and after some rather small changes, editor crashes again with Raw mesh is corrupt for LOD0, but this time for a mesh which earlier was HLOD.

Removing corrupted meshes resolves HLOD built crashes.
[2017.01.10-13.08.57:550][660]LogMaterialUtilities: Flattening material: Stone_LOD1
[2017.01.10-13.08.57:554][660]LogMaterial: Missing cached shader map for material FExportMaterialRenderer Stone_LOD1, compiling.
[2017.01.10-13.08.57:823][660]LogMaterial: Missing cached shader map for material FExportMaterialRenderer Stone_LOD1, compiling.
[2017.01.10-13.08.58:103][660]LogMaterialUtilities: Material flattening done. (Stone_LOD1)
[2017.01.10-13.08.58:209][660]LogTexture:Display: Building textures: M_LOD_Stone_03_38_Diffuse (BGRA8)
[2017.01.10-13.08.58:385][660]LogTexture:Display: Building textures: M_LOD_Stone_03_38_Normal (BGRA8)
[2017.01.10-13.08.58:528][660]LogMaterial: 0.01 seconds spent updating 1 materials, 1 interfaces, 0 instances, 1 with static permutations.
[2017.01.10-13.08.58:547][660]LogStaticMesh: Building static mesh LOD_Stone_03_38…
[2017.01.10-13.08.58:549][660]LogMeshUtilities:Error: Raw mesh is corrupt for LOD0.
[2017.01.10-13.08.58:551][660]LogStaticMesh: Built static mesh [0.00s] /Game/LOE/Maps/HLOD/Town1_HLOD.LOD_Stone_03_38
[2017.01.10-13.08.58:561][660]LogWindows: Windows GetLastError: The operation completed successfully. (0)
[2017.01.10-13.08.58:762][660]LogWindows:Error: === Critical error: ===
[2017.01.10-13.08.58:762][660]LogWindows:Error: Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:d:\build++ue4+release-4.14+compile\sync\engine\source\runtime\core\public\Containers/Array.h] [Line: 634]
[2017.01.10-13.08.58:762][660]LogWindows:Error: Array index out of bounds: 0 from an array of size 0