Many Mac users are reporting that their data files are getting 'un-zipped' as soon as they try to download them from their testing company web site. This causes problems for the upload utilities at GEDmatch.Com, since it expects to receive files in the same format as provided by the testing company. Check this (Thanks to Rodney Jewett for this hint):

In Safari "Preferences/General" the "Open safe files after downloading" at the bottom should be unchecked (the default is checked). If the box is checked, the file is automatically unzipped and the zip file is moved to the "trash".




Another option that has been suggested by another Mac user is to 'Hold down the OPTION key on the MAC keyboard when selecting the file for download on the testing company website.'