RepLayout -> Crash on Play (Line 660)

Hello all,
I’ve ran into an odd crash that isn’t giving me a lot of clues to go with.

The Crash info is the following:

Assertion failed: ArrayNum < ShadowArrayNum || Cmds[CmdIndex + 1].Type == ERepLayoutCmdType::DynamicArray [File:D:\Build\++UE4\Sync\Engine\Source\Runtime\Engine\Private\RepLayout.cpp] [Line: 660]

UE4Editor_Core
UE4Editor_Core
UE4Editor_Core
UE4Editor_Core
UE4Editor_Engine
UE4Editor_Engine
UE4Editor_Engine
UE4Editor_Engine
UE4Editor_Engine
UE4Editor_Engine
UE4Editor_Engine
UE4Editor_Engine
UE4Editor_Engine
UE4Editor_Engine
UE4Editor_Engine
UE4Editor_Engine
UE4Editor_Engine
UE4Editor_Engine
UE4Editor_UnrealEd
UE4Editor_UnrealEd
UE4Editor
UE4Editor
UE4Editor
UE4Editor
UE4Editor
kernel32
ntdll

This is the function in reference: SourceCode. From Lines 659-661:

if ( OwningChannel->Connection->bResendAllDataSinceOpen )
	{
		check( OwningChannel->Connection->InternalAck );

What do I do/how can I solve this?

Thank you for your time