There are payments with wrong Document Date (e.g. 23-May-1921 or similiar). These payments were imported (or updated with import).
Wrong DocDate was set in csv file (e.g. 15.12.2016 instead of correct 2016.12.15). Absence of validation is caused by the bug with id #PBA-78158 ("DocumentDate format for CSV import is not validated").
For future imports use correct format which is YY-MM-DD or YY.MM.DD. To make corrections to the already imported documents, please contact Odin Technical Support team.