digrocks

So several times over the past couple days I have had to re-download the Technic Launcher. While the launcher itself works fine, none of the modpacks do. After downloading, and installing a modpack, say, Blightfall for example, I can play for a short period, at which point, I save and shut down. When I reload the launcher, all packs have been uninstalled. After reinstalling a pack, and loading it up, everything seems to work fine. But then I try to load a save, or even create a new world, and it starts then goes back to the login screen. The only solution to this that I have found is to delete the entire launcher, as well as all of the packs, and start fresh with a new download. Please help! Thank you.