why cant i download a family tree to a thumbdrive

@dhutchins sr

You will need to use a FS partner solution (see the Solutions Gallery link at the bottom of the home page). These can pull a user-specified number of generations from Family Tree, then store the results on your computer in a format specific to the solution in use and/or export the data as an open standard (gedcom) file. In either case the information can be copied to a thumb drive.

Note that, as I understand it, Family Tree Maker is the only such solution that can transfer the sources.

Sorry, should have checked the up to date situation, FTM isn't currently listed in the Solutions Gallery.

If you want the sources included and have the necessary technical skills, you could try the open source program called getmyancestors which will pull the data straight to a gedcom.