When using a material function in a graph with a comment copied from that same material function will cause the material not to save. The error message that pops up says " ...Graph is linked to private object(s) in an external package.
Try to find the chain of references to that object(may take some time)?"
The material will give you an error message saying the graph is linked to private objects in an external package.
The material saves.
See original post for detailed screenshots on steps and result.
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