Having the same problem on a project migrated from 4.9 to 4.10.
I tried replacing the borked items with new ones but then get the same errors.
A build from the same folder contents works fine on a mac, with no errors on editor map load, no errors on compile, no errors on build.
A build from the same folder contents works on the initial map loaded from the exe on a PC, but fails to load new maps (resets current map instead). UE editor gives you a handful of “externally referenced” errors on map load. No errors on compile or build.
PC side is where I am getting the errors. Mac side seems content.