I just had a weird thing happen and I’m not finding the error message; maybe I’m the first ever to see it? Attempting to save a data directive, I get this message:
No matching constructor found on type 'System.String'. You can use the Arguments or FactoryMethod directives to construct this type.
It turned out that in an embedded query, I had a table criterion that a field must be “IN” a value list, and one of the listed values was left blank. I deleted it and the directive saved with no issue.
HTH