Get "Error parsing data in row...<date> is not a valid date value" message importing data (4246424)

When importing data that has dates with the format of dd-mon-yyyy, the import wizard is showing <error> in the preview window for all the dates.  When the import is run, it gives a "Error parsing data in row... is not a valid date value" error message as well.  There is nothing wrong with the date format being imported, but for some reason it thinks it is not valid.

This issue is fixed in Toad for Oracle 12.0. This version can be downloaded at https://support.quest.com/softwaredownloads.aspx?pr=268435520.