Solution
- Check the Java version if it is 1.6 and above to be able to connect with the AppStudio Exporter Plugin
- Open Safari (no other browser) and open http://javatester.org/version.html, it will give you your java's version.
If you want to download the latest version of Java http://java.com/en/download/index.jsp
Note:- In case you are still not able to log in in App Studio Exporter than try to log in on https://my.appstudio.net