[4.7.0, 4.6.1] - Inherited Macro causes "Graph is linked to private object(s) in an external package" error


Although this issue has already been discussed in various posts, I would like to report it as a bug because this issue corrupts project files!

You can reproduce the issue;

Step 1: Create a new actor BP, and create a new Macro with no input/output parameters. - (Actually, it really doesn’t matter whether you create input/output parameters or not, because this issue will corrupt your project in any case.)

Step 2: Compile, and Save.


Step 3: Right click on the BP you created in Step 1, and create a new Child BP by selecting “Create Blueprint based on this”.

Step 4: Inherit the macro from the parent BP.

Step 5: Try to compile, and save. - Although Child BP compiles successfully, it cannot be saved! You get the following error messages, in addition to corrupt project :frowning:

I have read the official UE4 documentation on Macros, but was unable to clarify if macros can be inherited or not.

Please forgive me if I’m missing something, but

  • If we can, it should compile and save.
  • If we can’t, there should be no inherited macro selection in Child BP context sensitive pop-up window.

For both cases, this issue is a bug.

Kind Regards,

Hi Dynamo,

Thanks for the report! I was able to reproduce this behavior in 4.7.1 as well as our internal build, so I have entered a bug report for the developers to work with (UE-11121). I’ll let you know as soon as I see any update. Thanks again!

Hi Dynamo,

Just wanted to let you know that the problem was that Local Macros aren’t meant to be inherited by child Blueprints. A fix was put in for 4.8 to make sure it doesn’t show up as a searchable option in child BP Event Graphs. Thanks again for bringing this to our attention!

Thank you very much Ben!

I have to admit that I’ve just learned the local macros aren’t meant to be inherited by child BPs, thanks to your kind reply. It was an ambiguous case, at least for me. Actually, a clarifying update to macro documentation would be great. (Forgive me if that information is already somewhere there, and I’m missing it.)

And, I’m very happy to see that UE4 development team is prioritizing & working hard on fixing bugs. With respect to all your kind efforts in recent months, I’m keeping my fingers crossed for a stable release :wink:

Thanks again for your kind reply!