I have a scriptable data connector hooked up to a protocol function (when you select the row in the table, a protocol runs and returns a report to a dynamic content container in the same page). 

When I select a row, I get an error that I can't interpret (see below). 

Does anyone have any idea what this error is? It is especially puzzling because I basically copy-pasted a protocol I wrote 4+ years ago and updated the data connector to use the id field that applies to the current data, and made a new protocol to put the results into the content container. But the basic machinery / structure of the protocol is the same as another one that works correctly.