[BUG] Blueprint fails to compile

Yesterday i was making some changes to my project created from First Person Blueprint. Before i quit the editor yesterday i played the game so there was no issues at all. However today when i opened that map i get the below error. I cant even close Rocket. It simply goes to Not Responding and hangs forever:

LogBlueprint:Error: [compiler] Error COMPILER ERROR: failed building connection with 'object'Actor' is not compatible with object'TextRenderActor'' at  SpawnActor   
LogBlueprint:Error: [compiler] Error Pin  Target   must have a connection
LogBlueprint:Error: [compiler] Error Variable node  Get TextRender   uses an invalid target.  It may depend on a node that is not connected to the execution chain, and got purged.

I had no issues yesterday. Today when i press compile Rocket just hangs up. (Crash Dump was created inside Log Folder). Issue is only with this project. Below is the result from log folder.

[0039.18] LogWindows:Error: appError called: Invalid object in GC: 0x000007fc2a0a0dc0, ReferencingObject: MyCharacter_C /Game/Blueprints/MyCharacter.Default__MyCharacter_C, ReferencingProperty: ObjectProperty /Game/Blueprints/MyCharacter.MyCharacter_C:CallFunc_GetPlayerCharacter_ReturnValue_301EA0654828767A1A15DFBBF2D7AD82

[0039.18] LogWindows:Error: Windows GetLastError: The operation completed successfully. (0)
[0039.18] LogCrashTracker: 

[0039.18] LogThreadingWindows:Error: Runnable thread TaskGraphThread crashed.
[0039.18] LogCrashTracker: 

[0039.18] LogWindows: === Critical error: ===
Unhandled Exception: 0x00000001

[0039.18] LogWindows: Invalid object in GC: 0x000007fc2a0a0dc0, ReferencingObject: MyCharacter_C /Game/Blueprints/MyCharacter.Default__MyCharacter_C, ReferencingProperty: ObjectProperty /Game/Blueprints/MyCharacter.MyCharacter_C:CallFunc_GetPlayerCharacter_ReturnValue_301EA0654828767A1A15DFBBF2D7AD82

Address = 0x43a4811c (filename not found) [in C:\Windows\system32\KERNELBASE.dll]
Address = 0x2ca9765b (filename not found) [in G:\Rocket\Engine\Binaries\Win64\RocketEditor-Core.dll]
Address = 0x2c9b2484 (filename not found) [in G:\Rocket\Engine\Binaries\Win64\RocketEditor-Core.dll]
Address = 0x2c3f0ec0 (filename not found) [in G:\Rocket\Engine\Binaries\Win64\RocketEditor-CoreUObject.dll]
Address = 0x2c3e91d5 (filename not found) [in G:\Rocket\Engine\Binaries\Win64\RocketEditor-CoreUObject.dll]

I have attached my project here. Inside the Logs folder you can see the complete log and Crash Dumps.
Inside the MyProjectile you can see Text Render (Collapsed) Node which contains the spawn actor.

I now have this issue. I have a fairly typical Vehicle setup, but I’m being told the Mesh variable is an invalid target. I’m suddenly unable to compile the blueprint and can’t seem to work around it?

Hey guys,

I had a couple of questions since this is an older issue–

  1. Satheesh - Are you still experiencing the compile error and/or crash on the latest Rocket Beta build?

  2. Luke - Are you getting just the compile error or are you getting the crash as well? If you are just getting the compile error, could you provide a screenshot of your blueprint setup showing the error?



I’m getting just the error. It seems ‘GetSocketLocation / Rotation’ won’t accept a mesh component, but it will accept the root component if it is a mesh component. I’ve worked around this for now, but in future this will be a problem. Image attached of an example.

Hey Luke,

Was this setup used in a WheeledVehicle blueprint? I tried to repro with a blueprint based on WheeledVehicle using the root Mesh as well as added Static/Skeletal meshes and was not able to generate this compile error.

Also, what was the workaround you implemented?



Hi Steve,

I have a pawn class derived from AWheeledVehicle that I based the blueprint on. If I use the mesh variable directly that is exposed to me in the blueprint editor, it throws the invalid target error. The mesh component is coincidentally the root component. If I get the root component and use that, it works as expected.

Hey Luke,

We were able to reproduce this issue internally and have filed a defect report to have it fixed. Hopefully we will have a fix implemented in the next Rocket Beta build.



Hey Satheesh,

I have submitted this for the team to look at. When you reopened the project did you make any changes before you when to compile the blueprint again.

Best Regards,


No i didn’t do anything. When i opened the project i just pressed Play In button and it said “One or more blueprints failed to compile”. When i press compile nothing happens. It just hangs up.

One more thing i noticed just now. If you open the MyCharacter or MyController Blueprint (I don’t exactly remember which one) and press compile you’ll get a Fatal Error message and Rocket crashes.