Why do I get the error message when importing 'familyname is invalid'?

The error message 'familyname is invalid' may have the following causes:
  • There must be a value in the familyname column
  • A familyname has to start with a letter
  • The column name must be in the first line, i. Tiitel lines must be deleted in Excel
  • The list must be in Excel in the first tab, i. it is best to delete all other tabs
Only when all errors have been fixed will the liste be imported.