Float UMaterial Parameter throws error in matinee when Exporting Movie

I’m using some float material Parameter tracks in matinee to control some materials. When Trying to render the clip out through clicking ‘Movie’ I get the following error:

Can't save /../ Nebula__sovereign_fires_back.umap: Graph is linked to private object(s) in an external package.
External Object(s):

Deleting the tracks (I have two in the project) with the float U material Parameters will allow the render to continue.


-Create a material with a scalar paramater.

-In Matinee: New group (I’ve got the Decal actor selected when creating a new group) > Add Float Material Parameter Track.

-Try and Export a movie.

Thanks in advance for any suggestions. Please let me know if you need any more information.

Hi -

Following your reproduction steps I am not getting any error messages. I have attached my Test Project below, can you have a look and make adjustments to make it closer to your project?

Thank You -

Eric Ketchum


Hi Eric, Unfortunately (or fortunately) I cannot reproduce the error also.

In the project I initially created the Matinees by right clicking in the content browser and creating a matinee sequence there, before dragging it into my level and animating. I could not export the result. Deleting the Umaterial Paramater tracks allowed me to export.

In the same project I went ahed and created a matinee (By using the top toolbar, not the content browser) and everything worked fine. (I copied the animation data to the new matinee, Material Paramaters and all)

I’ve tried a couple things now and cannot bring up the error in any other project. The error is still showing in the original level however.

I’ve migrated a version of the scene and attached it. If there’s anything else I can help with please let me know.

Hi Lukewade2 -

Thank you for your test project that helped me narrow down the issue. I was able to reproduce it now and have entered a bug report as UE-20123. I will keep you informed here as we investigate a solution to this issue, though it might come back as designed. In the meantime, I would recommend keeping the created InterpData File that gets created when you add a Matinee Actor from the Viewport Matinee dropdown.

Thank You Again for your help -

Eric Ketchum