There seems to be a issue with the garbage collector and blueprints / arrays in Unreal Engine 4.14.
These are the assets I got from my project. I have checked the blueprints and re-saved them and it still happens.
Fatal error: [File:C:\UnrealEngine-4.14\Engine\Source\Runtime\CoreUObject\Private\UObject\GarbageCollection.cpp] [Line: 547]
Invalid object in GC: 0x000002753f800000, ReferencingObject: IntProperty /Game/RingMenuConstKit/WB_RingMenu.WB_RingMenu_C:DeselectAllButtons.Temp_int_Array_Index_Variable, ReferencingObjectClass: Class /Script/CoreUObject.IntProperty, Property Name: Next, Offset: 48, TokenIndex: 2
Fatal error: [File:C:\UnrealEngine-4.14\Engine\Source\Runtime\CoreUObject\Private\UObject\GarbageCollection.cpp] [Line: 547]
Invalid object in GC: 0x000000003e3a0946, ReferencingObject: IntProperty /Game/UI/Menu/Settings/BP_UMG_GraphicsSettings.BP_UMG_GraphicsSettings_C:Load.CallFunc_Add_IntInt_ReturnValue, ReferencingObjectClass: Class /Script/CoreUObject.IntProperty, Property Name: Next, Offset: 48, TokenIndex: 2
Fatal error: [File:C:\UnrealEngine-4.14\Engine\Source\Runtime\CoreUObject\Private\UObject\GarbageCollection.cpp] [Line: 547]
Invalid object in GC: 0x000001e53ea00b24, ReferencingObject: IntProperty /Game/Blueprints/Characters/Dinosaurs/BP_BaseDinosaur.BP_BaseDinosaur_C:SetProgressionTier.Temp_int_Array_Index_Variable, ReferencingObjectClass: Class /Script/CoreUObject.IntProperty, Property Name: Next, Offset: 48, TokenIndex: 2
Fatal error: [File:C:\UnrealEngine-4.14\Engine\Source\Runtime\CoreUObject\Private\UObject\GarbageCollection.cpp] [Line: 547]
Invalid object in GC: 0x0000025b3f800000, ReferencingObject: TextProperty /Game/Blueprints/GameModes/BP_GameMode_OpenWorld.BP_GameMode_OpenWorld_C:DeleteAccount.CallFunc_Conv_StringToText_ReturnValue, ReferencingObjectClass: Class /Script/CoreUObject.TextProperty, Property Name: Next, Offset: 48, TokenIndex: 2
Notice how all 4 fatal errors are all being triggered by some type of temp_int / array index variable. The crashes are more likely to happen if you change maps back to a main menu map, then load the game map again. Most likely due to the garbage collector running again.
Please note that these crashes don’t happen in 4.13.1
I changed the project settings and enabled single threaded garbage collection and didn’t make any differences.
I am using the 4.14 branch on github and not the preview from the launcher. There are no custom engine changes to the code to break this.
Callstack:
https://dl.dropboxusercontent.com/u/81052782/ShareX/devenv_2016-10-28_22-29-07.png
https://dl.dropboxusercontent.com/u/81052782/ShareX/devenv_2016-10-28_22-29-55.png