If your data synch with School Cloud Systems (via the API) is giving you a warning that certain students are not in classes, please check in Admin > Config > Tutors that all your forms have a teacher assigned to them (particulary any new form name set up recently).
You can link teachers to forms by clicking on Assign, then select the Year and/or Form, click Update to Save. Once completed, re-synch your data with School Cloud Systems and this error will be resolved.
