Voltz not working after playing in single player crash {Please help}

[Shadowman453]

So Today I was  playing in single player and after launching a red matter missle and an anti matter missle by accdient I crashed volts. After i closed the window and opened the Technic launcher the volts window did not pop up after I had waited 30 minutes so I took my friends suggestion and reset the mod pack. now I cant open it And when i click play it says error installing mod pack please check system.