This morning when I ran the SQL Developer, this will not finish start, and stays in the next screen (the language is set to Spanish);
After fifteen minutes, has given me to investigate, looking on google I have seen that there may be a problem with the configuration and in many forums it is recommended to delete the directory system4.1.1.xxxx.. In my case it is in the C:\Users\anavarror\AppData\Roaming\SQL Developer folder (I use windows 7).
When you run SQL Developer again tells us if we want to load the old setup, in my case I had the previous version of SQL Developer. Here after several attempts I said no, if I say yes, the second time you restart the SQL Developer it hanged on “Windows are restored” again.
Select NO, of course, you can loose your previous configuration;
HTH – Antonio NAVARRO