Well. I was on the REAALLY old version of the Technic launcher, so i updated.
I see it all blue and fancy, now, but i can't play anything. I principally redownloaded it to play Hexxit, but it seems that i just can't.
I tried deleting .technic, .techniclauncher, i tried deleting the launcher itself.. I tried literally everything.
Here's a picture of the error i get whenever i want to start a modpack..