The Missing Candidates form opens when you click the Missing Candidates button on the Exam Importer form. If all is well, the form should be empty. However, if the imported file contains candidates who are not recognised by your system, the candidate numbers and candidate UCIs of the unrecognised candidates will be listed here. The reason for this may be that the results include those for external candidates. One possible solution is to add a skeleton pupil record for each of these candidates, but with a pupil type greater than that for Archived Pupils.