If you were unable to find your school and selected "None of the above" from the results list, you should then have been returned to your application form and allowed to manually edit the remaining entries.
In order to successfully fill out the school section, please be sure to replace “NOT FOUND” with the name of your school. You will also need to replace any "??" entries with the appropriate data, or enter "NA" in the state field if it is outside of the United States. Once you have entered all of the necessary information, you should be able to proceed without encountering a data validation error.