External sources warnings after updating project to 4.11

After converting my project to 4.11 I get many warnings when building about external sources being references for the basic cubes in the example maps. Should I be worried about it?

Can you post an image of the errors?

~ Jason

It is one message for every piece of level geometry in the fps blueprint example map. Started happening after converting the project to engine version 4.11.2 from 4.10.4. It also warns me of that every time I save the level.