This error will occur when there are no school details present in your school table, which may be due to a very recent migration to ScholarPack and you have not filled in the sections yet.
If you go to Admin > Config > Core set Up > School, or click on your school name at the top right of ScholarPack, you will find the School Details Table. Check that all details are correct regarding your school; click on Edit to input any missing data.
