Minecraft Launcher Closes When tarting Up Minecraft

When I press play on the launcher as the initializing bar gets to about halfway the whole launcher just closes and doesn't open Minecraft. this all stated happens after I opened the launcher and it told me there was a corrupted file but it had been fixed and then I pressed play and then closed halfway through loading Minecraft. it also came up the same message about the corrupt fie when I opened the launcher for the second time but now it open normally but then crashes halfway through loading the game.