UPDATE - FIX ]
Ensure the FBX skeletal mesh has a Material (in Blender). Many thanks to Yaroslav for his answer below.
[UPDATE - This is a bug. ]
I’ve never had any issue importing rigged meshes from Blender to Unreal before. In fact, it’s always been a breeze.
However, since I upgraded to the latest version, I’m getting a crash as soon as I click the import button to confirm import settings.
For instance, I created a simple cylinder mesh with, say, 4 linked bones in it so it moves like a bendy-straw. I’ve reduced the complexity of objects again and again but it seems to be something in this latest version that causes this crash regardless of the mesh or how many bones or even how those bones are linked.
To be sure, I re-installed an older version of Unreal (4.16.3) and all the files import fine!
Here is the error I get with the recent version:
Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:D:\Build\++UE4\Sync\Engine\Source\Runtime\Core\Public\Containers/Array.h] [Line: 614] Array index out of bounds: 0 from an array of size 0