I moved the save location to the correct folder to avoid Mac OS / Win access right issues
It now belongs into "Users/yourUserID/AppData/Roaming/Renpy/SpaceJourneyX... where all your save files are.
On Mac it is User/yourUserID/Library/Renpy/SpaceJourneyX...
Just drop the file there.
You can then leave it there, it will be automatically found in future.