Hey guys,

I worked on this problem for a couple of days and got a "solution". At first I set up all kind of Proxy-Settings:

• For NPM: npm config set proxy http://username:password@proxy.ac.co:port &
  npm config set https-proxy http://username:password@proxy.ac.co:port
• For GIT: git config --global http.proxy http://proxyuser:proxypwd@proxy.server.com:8080
• As enviroment variable: set http_proxy=http://username:pass@hostname:port &set https_proxy=https://username:pass@hostname:port

Be aware of the correct syntax with special characters in your username like "@":  set http_proxy=http://"user@name:pass"@hostname:port

After this settings I was able to use the command "vagrant up". But I wasn't able to reach localhost:5000. So I disconnected the networkcable and tried it again. After a few attempts it works. I connected the cable again and create my course with the Authoring Tool. To style my course I will follow this steps: https://github.com/adaptlearning/adapt_authoring/wiki/Modifying-the-Vanilla-Theme. 

You can download the Vanilla Theme separately if you don't use the Framework. With using the Framework there are some more issues while working in a proxy enviroment. Read this thread to get a workaround. 

I hope I was able to help some people. Let me know If you guys have another solution for working with both the Authoring Tool and the Framework behind proxies.

Thanks and Good Luck