KirbyPowers

So I was trying to launch Tekkit Classic and it said that I had to play offline. When I clicked on the "Play" button nothing happened for about 10 minutes. So I tried to delete the pack and re-download it, but I couldn't because it said, "Error unzipping a file for the following pack: Tekkit Classic Attempting to extract file tekkit-1.0.zip, but it did not exist. Please consult the modpack author." If you guys can help me with this I would GREATLY appreciate it.