Tekkit Crashes on Launch

[Gynwaith]

My Technic launcher runs just fine and I can choose between the different versions to run and such. But some of them work and some don't namely the only one I care about is Tekkit and it doesn't work. When I select it and click "Log In" it runs like it normally would and opens a separate window to start running in. The only thing is it gets to the Mojang screen and stays there for a few seconds and then it just closes. There isn't even an error or anything, it just closes. I've tried uninstalling and reinstalling countless times. This issue also occurs with Technic and HackSlashMine. Anyone know what might be wrong with it?