UE4Editor crash when clicking in the anim combobox in a PlayAnimation node

When editing a blueprint, I add a Play Animation node that is linked from a Cast to Skeletal Mesh node. The UE4Editor crashes almost every time that I click on the combobox to select what animation is to be played.

Sometimes the crash don´t happen when I was editing the blueprint but it happens playing the game, when the event that play the animation is triggered. I take the care of verify if my object is valid before the cast and call the Play Animation only if the cast is valid too.

Visual Studio output tell that is a assert failure:

Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:D:\BuildFarm\buildmachine_++depot+UE4-Releases+4.6\Engine\Source\Runtime\Core\Public\Containers\Array.h] [Line: 679]
Array index out of bounds: -1 from an array of size 4
UE4Editor.exe has triggered a breakpoint.

Sorry for my English

After reimporting the mesh, the problem was solved.