Guys, I need help. After apple logo, it says "an error occured preparing the sofware update." And it leads me to connect another computer with thunderbolt, but I don't have thunderbolt. Then, I tried to open with recovery mode, but it did not accept my password. When I tried with apple id, it accepted my password. But now, it says "The supplied icloud account was unable to unlock this volume." I cannot pass this screen. What should I do? If I buy thunderbolt, will it work?