[4.9, master] Save object error: Detaching from existing linker for %s while object %s needs loaded

We have strange error on saving blueprint.

I can minimise project with this problem.

Steps to reproduce problem:

  1. Download project from WO-5311-detaching-linker.zip (~100Kb)
  2. Open project with Unreal Engine 4.9+ (I tested on 4.9 and master a2f8af8fb)
  3. Open Mechanics\Base\BaseCharacter blueprint
  4. Save Mechanics\Base\BaseCharacter blueprint (press “Save this asset”)
  5. Press game in Editor (press “Play” button or Alt+P key)
  6. Stop (press Esc key)
  7. Save Mechanics\Base\BaseCharacter blueprint again (press “Save this asset”)

Expected result: blueprint saved.

Actual result: Crash.

[2015.10.22-12.04.41:327][535]LogTemp: Playing ActiveSound: EndPlayInEditor_Cue
The thread 0xaa8 has exited with code 0 (0x0).
[2015.10.22-12.04.42:426][566]Cmd: OBJ SAVEPACKAGE PACKAGE="/Game/Mechanics/Base/BaseCharacter" FILE="E:/Work/W1/W1SaveFail/Content/Mechanics/Base/BaseCharacter.uasset" SILENT=true
Assertion failed: !HasAnyFlags(RF_NeedLoad|RF_NeedPostLoad) [File:C:\Work\W1\UnrealEngine\Engine\Source\Runtime\CoreUObject\Private\UObject\UObjectLinker.cpp] [Line: 102] 
Detaching from existing linker for E:/Work/W1/W1SaveFail/Content/Mechanics/Base/BaseCharacter.uasset while object W1PeriodicRegeneration /Game/Mechanics/Base/BaseCharacter.Default__BaseCharacter_C:EnergyComponent.W1PeriodicRegeneration_0 needs loaded
UE4Editor-Win64-Debug.exe has triggered a breakpoint.

UE4Editor-Win64-Debug.exe has triggered a breakpoint.

Hi Bozaro,

I see that you also posted this issue on the Unreal Developer Network. We are going to focus our efforts and will respond to your post there.


I found workaround: https://github.com/EpicGames/UnrealEngine/pull/1700