Hello Leon,
There are no switches for something like that. The most likely answer is a spelling error in one of the 41 element names in the source list of elements. The programming editor can not check those for syntax errors as they exist on a form outside the scope of the current form.
If you run the code
Write(@XListvalues(@FN,"INVOICE!FACTFACT"))
and it works. We know that Sesame can access that form(remember XLookup and kin uses form and element names, not database and field names) and the FACTFACT element.
So what you can do to determine what element name is spelled wrong is open the Invoice form in Search/Update and retrieve a record. Open the Mass Update Programming Editor. Copy and paste the entire source list of element names without the beginning and ending quote so you have
NAME;ADDRESS;NEXTELEMENT;ETC;ETC2
Then do a Replace and replace ; with = so you have
NAME=ADDRESS=NEXTELEMENT=ETC=ETC2
Then click Test Program. Since you are now compiling against the Invoice Form, Sesame can tell you what element name is not correct. Be sure not to run this Mass Update!!!
-Ray