Unknown Cook Failure

After compiling, received this error; Previously I was receiveing no errors other than ‘unknown cook failure.’

LogOutputDevice:Error: === Handled ensure: ===
LogOutputDevice:Error: Ensure condition failed: Cast(NewUpdatedComponent->GetOwner()) [File:D:\Build++UE4+Release-4.15+Compile\Sync\Engine\Source\Runtime\Engine\Private\Components\PawnMovementComponent.cpp] [Line: 16]
LogOutputDevice:Error: FloatingPawnMovement must update a component owned by a Pawn
LogOutputDevice:Error: Stack:
LogOutputDevice:Error: UE4Editor-Core.dll!0x00000000846995E6
LogOutputDevice:Error: UE4Editor-Core.dll!0x0000000084449B82
LogOutputDevice:Error: UE4Editor-Core.dll!0x000000008445B666
LogOutputDevice:Error: UE4Editor-Engine.dll!0x00000000696607C3
LogOutputDevice:Error: UE4Editor-Engine.dll!0x000000006964C556
LogOutputDevice:Error: UE4Editor-Engine.dll!0x00000000695D0884
LogOutputDevice:Error: UE4Editor-Engine.dll!0x00000000695EECAE
LogOutputDevice:Error: UE4Editor-Engine.dll!0x00000000691F6331
LogOutputDevice:Error: UE4Editor-Engine.dll!0x0000000069A1EA40
LogOutputDevice:Error: UE4Editor-Engine.dll!0x000000006A2F16D2
LogOutputDevice:Error: UE4Editor-Engine.dll!0x000000006A31B845
LogOutputDevice:Error: UE4Editor-Engine.dll!0x000000006A31B1FE
LogOutputDevice:Error: UE4Editor-Engine.dll!0x000000006A1CCF7E
LogOutputDevice:Error: UE4Editor-Engine.dll!0x00000000698DC0C6
LogOutputDevice:Error: UE4Editor-UnrealEd.dll!0x0000000071458BE7
LogOutputDevice:Error: UE4Editor-UnrealEd.dll!0x00000000714853ED
LogOutputDevice:Error: UE4Editor-UnrealEd.dll!0x00000000714A1874
LogOutputDevice:Error: UE4Editor-UnrealEd.dll!0x0000000070F8626B
LogOutputDevice:Error: UE4Editor-UnrealEd.dll!0x0000000071792196
LogOutputDevice:Error: UE4Editor.exe!0x00000000B436DEE3
LogOutputDevice:Error: UE4Editor.exe!0x00000000B435EB40
LogOutputDevice:Error: UE4Editor.exe!0x00000000B435EBBA
LogOutputDevice:Error: UE4Editor.exe!0x00000000B4370A29
LogOutputDevice:Error: UE4Editor.exe!0x00000000B43722B6
LogOutputDevice:Error: KERNEL32.DLL!0x00000000AD1B2774
LogOutputDevice:Error: ntdll.dll!0x00000000ADDD0D51
PIE:Error: Error Blueprint Runtime Error: Attempted to access BP_Manakin2_C_0 via property CallFunc_FinishSpawningActor_ReturnValue, but BP_Manakin2_C_0 is pending kill from function: ‘ExecuteUbergraph_BP_EnemySpawner’ from node: Spawn Default Controller in graph: EventGraph in object: BP_EnemySpawner with description: Attempted to access BP_Manakin2_C_0 via
property CallFunc_FinishSpawningActor_ReturnValue, but BP_Manakin2_C_0 is pending kill
PackagingResults:Error: Error Unknown Cook Failure

can anyone help out? Line16 error - how do I find this? Do I need VS - this looks like an engine bug -
The BP_Manakin looks like maybe it is clipping the ground and not spawning.