Any change to scene comp results save error: 'Graph is linked to external private object'


I ran into this issue today.

  1. Start a new project, any time, I used FPS example
  2. Add new blueprint, make the parent an actor
  3. Add new blueprint, make the parent a scene component
  4. Add the component to our new actor
  5. Save everything, there should be no errors at this point
  6. Add a new function to the scene component
  7. Have the actor cal the function in eventTick or anywhere
  8. Change the function, add an argument, return value, anything
  9. Save all and you should now get the error.

EditorErrors:Warning: Warning Can’t save …/…/…/…/…/…/Users/DaveB/Documents/Unreal Projects/CropTesting/Content/Crops/Final/BP_Field.uasset: Graph is linked to external private object (unknown culprit) (unknown property ref)

I was able to reproduce this with an actor in the level, or like here, with none.
If this isn’t an actual bug and me just using things wrong, please feel free to shout at me. If you need any more details, just shout.


Hey Dave,

I attempted to reproduce this but I didn’t get the error. Here is what I did:

  1. Created a new FPS project

  2. Added a new Actor class bp

  3. Added a new SceneComponent bp

  4. Added the SceneComponent bp to the Actor bp

  5. Saved all

  6. Added a new function to the SceneComponent bp

  7. Added the function to be called on a EventTick

  8. Changed the function to have a Bool output

  9. Saved all

If I missed anything, please let me know. Please include some screenshots or a small test project if possible.

Hi TJ,

Apologies, I thought I got all the steps last time, but it looks like I didn’t, my bad.

  1. Create new FPS project
  2. Added new actor class BP
  3. Added new scene component BP
  4. Saved all
  5. Add dummy function to eventTick on Scene Compoent
  6. In Actor construction script add scene component
  7. Compile, save, all should be well
  8. Change scene component dummy function
  9. Compile, save, all is fine
  10. Recompile Actor (sometimes error, sometimes fine)
  11. Save and get error message

Hope that helps,

alt text

Ignore the sc1 screen shot, it was when I was reproducing your steps and had the component added manually instead of via the construction script.

Thanks for the additional info. I was able to reproduce the issue on our end and after some further investigation I found it was recently reported. It is logged as JIRA UE-36567. You can follow that link to monitor the progress of the bug on our Public Issue Tracker.

The repro steps on that JIRA differ from yours but I believe the core issue is the same. I also commented on the internal version and referenced your post and repro steps.



Thanks TJ, a pleasure as always.