The problem is when I start Minecraft with a Forge profile and then create a new world or play with an existing one (even without mods), it loads briefly and then there's Shutting Down Internal Server. I have already tried several Forge versions (I play with 1.7.10) and reinstalled Java but it does not work.
I think the problem has already been described and solved here! Maybe it will help you
Thanks the answers there helped me a lot.
I'm glad!
Thanks for the star @Lockbuster!