Hi Kevin,

After I posted, I noticed that I should be able to change the WithFk list design such that the Lookup field has the Lookup Validator activated. Then the docs say, "An error will be displayed whenever you attempt to import a value that is not in the lookup's target table."

https://www.labkey.org/home/Documentation/wiki-page.view?name=lookupDefine#lookupvalidate

However, my above repo (plus turning on Lookup Validator), still inserts a row when the value cannot be mapped to the Simple list.

thanks for your help!

-Will