This user's Function Library will not save

This user's Function Library will not save. Hitting save returns the following error:

Can't save D:/4.7_Projects/EngineTransientBug 4.7/Content/Math.uasset: Graph is linked to private object(s) in an external package.
External Object(s):
/Engine/Transient

The .uasset is attached. It was created in 4.7.1. There do not appear to be any circular references inside the BP Library.

Reproduced in 4.7.2 binary and Main (//depot/UE4/Promotable-CL-2471062)

1. Move the attached Math.uasset into the Content folder of any project
2. Open the Math Blueprint Library
3. Save

Results:
Can't save D:/4.7_Projects/EngineTransientBug 4.7/Content/Math.uasset: Graph is linked to private object(s) in an external package.
External Object(s):
/Engine/Transient