Let's pick some names to explain what I think you might have here:
ParentTable:: PrimaryKey = PortalTable::ForeignKey, "Allow creation of records via this relationship, selected for the portal table"
That's what I think you have here.
Any chance "ForeignKey" is a calculation field? (or modification is prohibited in field options?)
If so, then entering data in the bottom blank row of your portal triggers filemaker to make a new record in the PortalTable and then attempts to store the value of PrimaryKey in the the ForeignKey field. If modification of this field is somehow prohibited, you get the error message you've reported.
That did it. I changed the "ForeignKey" field to text with a calculated result. I guess I'm not still not totally clear on the behavioral differences of a calculation field that returns text and a text field that is based on a calculated entry...
Thanks as always
Why is it a "calculated result" field? Simple data fields are usually all you need for this type of field in this type of relationship.
Guys I am also facing same issues but in my case three to four calculation field with relationship
how to resolve the issues ???