Believe I've found a work-around at least for City of Wilmington's environment -

1.       Problem occurs due to the file name already being contained in the Files table.

2.       The source of the problem seems to be in stored procedure AddFile.

     SELECT SCOPE_IDENTITY() is returning NULL because it’s outside the IF .. ELSE block. When the file name exists in the Files table the UPDATE block of the IF statement runs but NULL is still returned. Fix seems to be to move the SELECT SCOPE_IDENTITY() statement up into the INSERT block of the IF statement so that a valid identity is returned when inserting new files and nothing is returned when updating an existing file name.