Cannot Import ... The related entity has already been configured with a cascading or parental relationship. Select a different relationship type.

I am attempting to import a solution into a Dynamics 365 Online environment and am getting the error:

 I have checked Entity X's N:1 relationships and there is only one parental.  I do not understand why this is happening.  And why would I be able to configure it that way and then it fails on import.  Seems a little late in the game.