Can't save anything after updating to 4.2.0.

After using the convert option and copy option the system will no let me make and save materials used in the 4.1 version.

Can’t save …/…/…/…/…/…/Users/kevin/Documents/Unreal Projects/RPGSystem_Demo 4.2/Content/TextureLibrary/MaterialFunctions/MAT_Ground.uasset: Graph is linked to object(s) in external map.
External Object(s):
/Engine/Transient

Try to find the chain of references to that object (may take some time)?

It seems to work after closing the editor and remaking the changes.