When i opened minecraft it used to work flawlessly. i wanted to make my own mod, so i installed java 7 and forgot that on linux java 7 doesnt work for minecraft. (im using ubuntu.) so i installed java 7 jdk, and when i opened minecraft and logged in i would get a black screen because of java 7. i already had openjdk6 on the computer and i tried lots of ways to delete java 7. but after trying to delete it in many ways, java 7 icons were still there. Also minecraft wouldent even start after trying to uninstall java 7.
I also installed minecraft forge and deleted the folder meta-inf. (those folders are not the problem.)
I also installed minecraft forge and deleted the folder meta-inf. (those folders are not the problem.)