Character BP broken after upgraded to 4.4

Development Programming & Scripting
21

Hey ,

I’ve been struggling with this bug as well today. When I completely recreate the character blueprint in question I’ve noticed that only when I start implementing the blueprint into other blueprints (behavior tree task, and an actor) does the character blueprint break - it appears to fail at saving, and then results with the errors described by other users in this thread.

Unfortunately, I haven’t been able to successfully reproduce the issue in an empty project. However, here are the messages that occur for the character blueprint right before it breaks in my project (prevents mesh selection/null values, shows failed import when editor loads):

22

Hi ,

What steps are you taking to call this blueprint into other blueprints? Does this only occur on the one character asset or any that you have in your project?

23

Hey ,

The failed save occurs only in one character blueprint in my project. However, when I recreate the blueprint from scratch, somewhere along the re-implementation it fails to save the blueprint, breaks/corrupts the blueprint, and children of that character blueprint start throwing the import errors when the editor is loaded.

My classes:
CCMinion (Parent: Character)
CCMinionTest (Parent: CCMinion)

CCMinionTest is getting the import errors (arrow, movement, mesh) as it was a child of CCMinion before the failed save. Re-parenting CCMinionTest with CCMinion doesn’t seem to accomplish anything (same import errors), and creating a new blueprint that parents CCMinion after the failed save does not cause import errors, but has broken functionality since its values are stuck at null.

It’s worth noting that the components still appear under the “Components” tab in the blueprint editor, but are not modify-able, and a different naming convention is used in the child class (just means they’re null perhaps?):

1049×796 208 KB

1049×796 319 KB

CCMinion Usage:

Building (Parent: Actor) - Array variable, Return value on function.

MinionController (Parent: AIController) - array, variable, function parameter

TaskAttackEnemy (Parent: BTTask_BlueprintBase) - Accesses variable from MinionController

TaskFindEnemy (Parent: BTTask_BlueprintBase) - Accesses array from MinionController, sets variable in MinionController

CCMinionTest as child

CCMinionTest Usage

Building (Parent: Actor) - Spawns actor CCMinionTest

I’m going to spend some more time trying to reproduce this error more consistently/transparent. If any staff would like to take a look at my project please let me know and I’ll upload to my dropbox.

24

That may be helpful. I would be happy to take a look at what is going on. Thank you!

25

gamepatriot.com/ue4/Castle2.

Using UE 4.4, Windows, and the project contains “Strategy Game” assets/code (4.4).

26

Hi everyone,

I have a bit of good news here. We were unable to reproduce this bug in the most recent internal build. This means that there should be a fix out for this in a later build. For now, I would recommend sticking with the engine version that you have that is not causing this break to occur, once I have more information on a timeframe for release I will update here. Thank you!

27

Hi , that’s great news! Can we expect this fix in the recently released 4.41 update?

28

I recently come across this bug too, which has kinda destroyed months of work. If we leave the blueprints as is, are we able to expect they will start working again with a new build?

I am currently using 4.4.1

Rebuilding the entire character blueprint would be a big task =(

29

Unfortunately I do not have an exact timeframe on the release of this fix. However, it potentially could make it into 4.5. Keep a look out for the release notes!

30

I’ve just recently join this club of people that is affected. However I did not get this problem upon upgrading to 4.4 but just realized one of the parent class of our BP is affected. Surprisingly though the child class worked fine for days.

But upon digging through our repository, I realized it was already bugged for at least 4-5 version before. However I manage to restore the Blueprint the version RIGHT before the crash. The blueprint looks fine, opens fine, and edits fine on the surface, however if I attempt to MOVE the blueprint to another folder. It crashed.

I’m not sure if this helps, but I’ll put it here .

    !Id:ea4253df2fefb57712c7100a0832c835
    
    Unknown exception - code 00000001 (first/second chance not available)
    
    Assertion failed: !HasAnyFlags(RF_NeedLoad|RF_NeedPostLoad) [File:D:\BuildFarm\buildmachine_++depot+UE4-Releases+4.4\Engine\Source\Runtime\CoreUObject\Private\UObject\UObjectLinker.cpp] [Line: 94]
    Detaching from existing linker for ..//..//..//..//.
31

Additional Comment. There are also some other strange behavior about this ‘would-be-broken BP’

Apparently , it is referencing some transient class and refused to be deleted nor re-referenced
Blueprint /Game/PC_Blueprints/AI/BP_BasicAI.BP_BasicAI is in use.

Running the editor with ‘-NoLoadStartupPackages’ may help if the object is loaded at startup.

External referencers of Blueprint /Game/PC_Blueprints/AI/BP_BasicAI.BP_BasicAI:
Function /Engine/Transient.TRASHCLASS_BP_InfantryPawn_189:Function_352 (root) (1)
0) None
Function /Engine/Transient.TRASHCLASS_BP_InfantryPawn_189:Function_349 (root) (2)
0) None
1) [[native reference]]
BlueprintGeneratedClass /Game/PC_Blueprints/Characters/BP_InfantryPawn.BP_InfantryPawn_C (4)
0) None
1) [[native reference]]
2) [[native reference]]
3) [[native reference]]
BlueprintGeneratedClass /Game/PC_Blueprints/Characters/BP_InfantryPawn.SKEL_BP_InfantryPawn_C (4)
0) None
1) [[native reference]]
2) [[native reference]]
3) [[native reference]]
Function /Game/PC_Blueprints/AI/BP_AIControllerInfantry.BP_AIControllerInfantry_C:InitBehaviorTree (1)
0) None
Function /Game/PC_Blueprints/Characters/BP_InfantryPawn.BP_InfantryPawn_C:ReceiveBeginPlay (1)
0) None
Function /Game/PC_Blueprints/Characters/BP_InfantryPawn.BP_InfantryPawn_C:UserConstructionScript (2)
0) None
1) [[native reference]]
Function /Game/PC_Blueprints/Characters/BP_InfantryPawn.SKEL_BP_InfantryPawn_C:ReceiveBeginPlay (1)
0) None
Function /Game/PC_Blueprints/Characters/BP_InfantryPawn.SKEL_BP_InfantryPawn_C:UserConstructionScript (1)
0) None

Shortest reachability from root to Blueprint /Game/PC_Blueprints/AI/BP_BasicAI.BP_BasicAI:
Blueprint /Game/PC_Blueprints/AI/BP_BasicAI.BP_BasicAI [target] (standalone)

32

@ what is the recommendation for this issue? We are trying to upgrade from 4.4.3 to 4.5 and are seeing similar issues.

33

Have you attempted to pull the character out of the content filepath, migrate the project, then return the character to the content folder? I am not certain if this will work however it may prevent the file from receiving the error. At present I do not have a viable workaround for this issue as it has been fairly difficult to track down and discover what exactly is occurring.

34

I’m also facing this issue in 4.4.3, will upgrading to 4.5 fix this issue?

As someone else said my project too is getting increasingly corrupt with each passing day. Each time I click on play there’s a good chance of it crashing and after that the project always crashes on startup until I rollback to an older version of the character blueprint.

35

Hi

I just converted from 4.3.1 to 4.5.1. My character seems working fine so far, except “Suggest Projectile Velocity” blueprint node stopped working.

Here is the new ticket for that issue: 4.5.1 Suggest Projectile Velocity stopped working - Programming & Scripting - Epic Developer Community Forums

36

Just wanted to confirm 's observation below - after moving to 4.3.1 I’m no longer having issues, my character BP works again.

37

I’m getting this in 4.5.1 and it’s ground my game to a complete hault. I keep trying to rederive the player but it keeps breaking when I reload the editor or package the game.

38

Hi ,

Can you describe what is happening to your player character? Are you getting the “none” variants within the defaults tab? What actions did you take before seeing this error occur?

39

Just in case you didn’t realize, this post was also mine: My Blueprint Nightmare (possible bug) - Blueprint - Unreal Engine Forums.

Yes, my character Mesh is suddenly None.

My full response went over the character limit, so please find my response in that forum post. But I will do a Bug Report tonight.

Also, should I be getting notified when someone replies to me on answerhub? I only found your reply by searching through my profile activity to get back to this post.

40

Hi ,

I am remarking this answer as accepted for tracking, we will continue the conversation on the forums. Thank you!