Why would I get this message? I did a search but apparently nobody else has run into this.

After awhile I did discover someone who had this problem and the only reply was that a primary key needed to be defined.

I have a primary key though, so that's not the problem.

Leave it to me to be the only the 2nd person on the whole planet to run into this issue. Figures.

FIXED IT......... so NEVERMIND .... Never determined the problem but I deleted the model and started over, and its replacement works fine.