Garbage Collection Crash

Garbage Collection is crashing when I stop play. It’s occuring in MarkObjectsAsUnreachable in the iteration of KeepClusterRefs. ObjectItem is nullptr which is causing the crash. It’s then spitting out the error:

Assertion failed: (Index >= 0) & (Index < ArrayNum) [File:d:\localprojects\unrealengine4.17\engine\source\runtime\core\public\Containers/Array.h] [Line: 596]
Array index out of bounds: -1 from an array of size 1