Hello everybody,i got very bad news.
First,my computer Gave me a screen with colors and I don't know what,then I sent it to the place that fixes computers,so he fixed it but I still cant open minecraft and other things,i will resend it now,if I am lucky,i will be able to play minecraft today or tomorrow,if I am not lucky,bye bye minecraft and kaisecraft :(
have you tried to install java again ?
if it still doesn't work try deleting the "launcher.pack.lzma" in ".minecraft" folder
i hope that helped you :)