I think i know why because one day i was playing tekkit and it froze my whole computer so i turned it off and when i tried to play it it would get to 100% version.json and the window wouldn't pop up so i tried to reset the pack and this came up "An error has occurred while attempting to delete 'C:\Users\Logan\AppData\Roaming\.technic\tekkitmain\mods\AdditionalPipes2.3.1-BC3.7.1.jar