SoggyBread

There already are threads discussing this. Uninstall java 6, and install java 7. At least that's what worked for me.

It looks like it's trying to call on a class that is not existent. You might be missing an API or something of that nature.

Check your folder and see if there is a crash log. Pastebin it and upload it here, so that we may gather more information to answer it properly, instead of taking wild guesses as to what might solve it.

Try downgrading. You most likely have newer versions of these files.

Blizz? I don't think there's anything in tekkit called blizz.

Uninstall java 6 then install java 7. https://www.java.com/en/download/manual.jsp I'm fairly certain this will fix it, as it did for me. If it does not fix it, or you cannot run java 7 on your machine, either wait for a hotfix or try a downgrade. You know you have uninstalled java 6 correctly when techniclauncher will error upon double click.