Message Text
Illegal nullable in tuple selector: first tuple selector cannot be nullable: variable1
Cause
The first lexicon selected in cts:value-tuples was given with the option "nullable". This is not allowed.
Response
Remove the "nullable" option from the first lexicon, or reorder the lexicons so that a nullable on is not the first.
Stack Overflow: Get the most useful answers to questions from the MarkLogic community, or ask your own question.