Retargeting animation causes crash every time

I’m getting the same issue as @Godwhacker
Retargetting works fine, exporting is fine, but as soon as I open an exported animation after retargeting, crash…every time.

I get this from the crash log:
Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:D:\build++UE5\Sync\Engine\Source\Runtime\Core\Public\Containers\Array.h] [Line: 758]
Array index out of bounds: 68 into an array of size 68

From what I can tell, it’s referencing the number of bones in the skeleton in the IK Retargeter asset…
The

The source skeleton has 87 bones, 70 with labels
The target skeleton has 85 bones, 70 with labels

so…the point is, I really don’t know what’s going on, but it’s annoying.