Blueprint Function Library - Can't save ... Graph is linked to private object(s)

I created “Blueprint Function Library”. Add 2 functions, and call first from secound. Save and restart editor. Then I do any change in this “library”. And when I try save it have error message:
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Can’t save …/…/…/…/…/…/…/Programming/UnrealProjects/resettlement/Content/Road/Blueprints/NewFunctionLibrary.uasset: Graph is linked to private object(s) in an external package.
External Object(s):
/Engine/Transient

Try to find the chain of references to that object (may take some time)?
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But it compiles and runs correctly.
I do something wrong?

What version you used, they fixed that one in 4.7.3, it the bug from 4.7.

UE-11185 A function in a Blueprint Function Library that references another function in that library cannot be saved after closing and reopening the project

Thank you for reply. I used 4.7.2. After update to 4.7.3 bug is gone.