Seventh... think you need to change the link in your first post... what you have there is just for you as it is the "manage" the upload link... we, normal users, need just the basic link to the theme on the stash... so if you log out of the stash, you should get that, ...
EDIT this is the link for the rest of us
https://stash.reaper.fm/theme/1067/ReaLax.ReaperThemeZip