I was attempting to set up a Junction Object in an organization with Person Accounts enabled to link Business Accounts with Person Accounts. I set up the Account Master-Detail on the custom junction object, but when I went to add the second Master-Detail I noticed that I couldn't select Account, but "Person" was available.
Assuming this meant Person Accounts (the child relationship name it provides is "Contacts", but Contacts was a separate option in the dropdown), I went ahead with this. Unfortunately, I received the following error on the final step for saving that I haven't had much luck searching for on Google. Any ideas?
Validation Errors While Saving Record(s)
There were custom validation error(s) encountered while saving the affected record(s). The first validation error encountered was "invalid domain".