Tekkit closing on Mojang screen

[McBliz]

Ok, so I've been having trouble worth my tekkit/technic pack launcher lately. Whenever I (try) to play tekkit, the launcheer will load, show the mojang screen, then close. I've reloaded the cache, changed modpacks, changed the versions (dev. to rec., then visa versa) and the same result aways happens. Tekkit works on another PC I use, but I have some servers (that I don't know the IP by heart) on the tekkit-not-working computer.

!! Help needed !!

- I use Norton Security

- This has just started happening

- I've seen another threads with the same problem happening but fixing it with skype..(?)