from 14 to 17? that certainly is not recommended.
but this: "after I type the password I get a black screen with the cursor" really isn't so bad after all - it means your x-serever started succesfully, but has nothing to do.
you should check out how linuxmint's login manager handles this, what programs it wants to start, and maybe one of them won't start anymore.
thus leaving X in limbo.