"A fatal error has occured"

When I try to download any version before 1.7. but after 1.3, the launcher downloads everything. It seems to be going good... but the launcher never disappears. I check the launcher log, and it says "A fatal error has occurred!" I don't understand any of the error details it gives me. The only way for me to play is to have a friend run it, then send me the files in a nice little .zip folder. It isn't the end of the world, but it's extremely annoying because I don't really see my friend on weekends, when I normally play Minecraft. When I get the files from him, everything runs fine. Is there a problem downloading all the files? I can replicate the error if you need it. I don't think it would be a technical issue because I can play several versions just fine, however I could be wrong. Thank you in advance for helping!