Trying To Set Instanced Static Mesh Data Crashes Engine

Hello, I’m getting a crash and I do not know what the cause might be.

In my Blueprint-System I have created various variables which enable the user to set Static Mesh and Materials of a bunch of Instanced Static Mesh Components. The problem is that when I try to set it a second time around (for example changing the Static Mesh) the engine Crashes with this Error here:

Assertion failed: (void*)((&ElementData[InstanceIndex]) + 1) <= (void*)(InstanceOriginDataPtr + CurrentSize) [File:D:\Build++UE4\Sync\Engine\Source\Runtime\Engine\Public\StaticMeshResources.h] [Line: 1259]

Does anyone know what this error might indicate. I have literally no idea why this error occurs, especially because it works without a crash the first time around, only the second time around I get this crash.

Thanks for the help!