UE4 crashes on attach to actor

I’m trying to implement a grab system for my race game but I can’t call attach to actor on a vehicle blueprint because it causes my game to crash.

This is my grab blueprint
https://blueprintue.com/blueprint/dy7-iyir/

And this is my function that disables all physics on to actor to be attached
https://blueprintue.com/blueprint/rh24pfst/

When the game reaches the attach to actor node the engine crashes and I get the following log

[2017.05.21-20.04.02:376][585]LogWindows:Error: === Critical error: ===
[2017.05.21-20.04.02:376][585]LogWindows:Error: 
[2017.05.21-20.04.02:376][585]LogWindows:Error: Fatal error!
[2017.05.21-20.04.02:376][585]LogWindows:Error: 
[2017.05.21-20.04.02:376][585]LogWindows:Error: Unhandled Exception: EXCEPTION_ACCESS_VIOLATION reading address 0xffffffff
[2017.05.21-20.04.02:376][585]LogWindows:Error: 
[2017.05.21-20.04.02:376][585]LogWindows:Error: UE4Editor-PhysXVehicles.dll!0x00000000C7EEAD5F
[2017.05.21-20.04.02:376][585]LogWindows:Error: UE4Editor-PhysXVehicles.dll!0x00000000C7EDEAF1
[2017.05.21-20.04.02:376][585]LogWindows:Error: UE4Editor-PhysXVehicles.dll!0x00000000C7ED52BB
[2017.05.21-20.04.02:376][585]LogWindows:Error: UE4Editor-PhysXVehicles.dll!0x00000000C7E8F6B5
[2017.05.21-20.04.02:376][585]LogWindows:Error: UE4Editor-PhysXVehicles.dll!0x00000000C7E8380E
[2017.05.21-20.04.02:376][585]LogWindows:Error: UE4Editor-Engine.dll!0x00000000D4FCD290
[2017.05.21-20.04.02:376][585]LogWindows:Error: UE4Editor-Engine.dll!0x00000000D5061CB4
[2017.05.21-20.04.02:376][585]LogWindows:Error: UE4Editor-Engine.dll!0x00000000D4FE1752
[2017.05.21-20.04.02:376][585]LogWindows:Error: UE4Editor-Engine.dll!0x00000000D43DA465
[2017.05.21-20.04.02:376][585]LogWindows:Error: UE4Editor-Core.dll!0x00000000DC61D84D
[2017.05.21-20.04.02:376][585]LogWindows:Error: UE4Editor-Core.dll!0x00000000DC61DC6D
[2017.05.21-20.04.02:376][585]LogWindows:Error: UE4Editor-Core.dll!0x00000000DC63CCEB
[2017.05.21-20.04.02:377][585]LogWindows:Error: UE4Editor-Engine.dll!0x00000000D53889D1
[2017.05.21-20.04.02:377][585]LogWindows:Error: UE4Editor-Engine.dll!0x00000000D53996A2
[2017.05.21-20.04.02:377][585]LogWindows:Error: UE4Editor-Engine.dll!0x00000000D4CC7B64
[2017.05.21-20.04.02:377][585]LogWindows:Error: UE4Editor-Engine.dll!0x00000000D4CCFF2D
[2017.05.21-20.04.02:377][585]LogWindows:Error: UE4Editor-UnrealEd.dll!0x00000000D2DF6D8E
[2017.05.21-20.04.02:377][585]LogWindows:Error: UE4Editor-UnrealEd.dll!0x00000000D3602156
[2017.05.21-20.04.02:377][585]LogWindows:Error: UE4Editor.exe!0x000000009CA4DEE3
[2017.05.21-20.04.02:377][585]LogWindows:Error: UE4Editor.exe!0x000000009CA3EB40
[2017.05.21-20.04.02:377][585]LogWindows:Error: UE4Editor.exe!0x000000009CA3EBBA
[2017.05.21-20.04.02:377][585]LogWindows:Error: UE4Editor.exe!0x000000009CA50A29
[2017.05.21-20.04.02:377][585]LogWindows:Error: UE4Editor.exe!0x000000009CA522B6
[2017.05.21-20.04.02:377][585]LogWindows:Error: KERNEL32.DLL!0x0000000020722774
[2017.05.21-20.04.02:377][585]LogWindows:Error: ntdll.dll!0x0000000022770D61
[2017.05.21-20.04.02:377][585]LogWindows:Error: ntdll.dll!0x0000000022770D61
[2017.05.21-20.04.02:377][585]LogWindows:Error: 
[2017.05.21-20.04.02:408][585]LogExit: Executing StaticShutdownAfterError
[2017.05.21-20.04.02:468][585]LogPhysics:Error: PHYSX: ( 0) eINVALID_OPERATION : PxScene::lockWrite() detected after a PxScene::lockRead(), lock upgrading is not supported, behaviour will be undefined.
[2017.05.21-20.04.02:469][585]LogPhysics:Error: PHYSX: (D:\Build\++UE4+Release-4.15+PhysX_Compile\Sync\Engine\Source\ThirdParty\PhysX\PhysX_3.4\Source\PhysX\src\NpScene.cpp 3020) eINVALID_OPERATION : PxScene::unlockWrite() called without matching call to PxScene::lockWrite(), behaviour will be undefined.
[2017.05.21-20.04.02:575][585]LogPhysics:Error: PHYSX: (D:\Build\++UE4+Release-4.15+PhysX_Compile\Sync\Engine\Source\ThirdParty\PhysX\PhysX_3.4\Source\PhysX\src\NpScene.cpp 218) eINVALID_OPERATION : PxScene::lockWrite() detected after a PxScene::lockRead(), lock upgrading is not supported, behaviour will be undefined.
[2017.05.21-20.04.02:578][585]LogPhysics:Error: PHYSX: (D:\Build\++UE4+Release-4.15+PhysX_Compile\Sync\Engine\Source\ThirdParty\PhysX\PhysX_3.4\Source\PhysX\src\NpScene.cpp 3020) eINVALID_OPERATION : PxScene::unlockWrite() called without matching call to PxScene::lockWrite(), behaviour will be undefined.
[2017.05.21-20.04.02:683][585]LogWindows: FPlatformMisc::RequestExit(1)
[2017.05.21-20.04.02:684][585]Log file closed, 05/21/17 17:04:02

All your Cast to AI Hell Dragon can return a null pointer that will result in Crashing your Engine. Make sure they are Valid before calling any other Funtionality on them.

EXCEPTION_ACCESS_VIOLATION reading address 0xffffffff <<< Basicly means Invalid Object address :stuck_out_tongue_winking_eye:

I’ve just tried adding the is valid node to it and the error continues… unfornately that’s not the problem

What if your Overlap return no Overlaped Actors?

Possible nullpointer

Possible nullpointer 2x

Possible nullpointer

I’ve added validation to all these points but the error persists… the logs show exactly the same error