You try follow some solution to fix your issue.
– fix 404 error : go to admin > system > permissions > roles , edit role administrator. In tab “role resources” change “all” to “custom” then change back “all” and click save it. The problem maybe about the role resources not updated when you setup there extensions.
– add the blocks in System/Permission> Blocks > http://nimb.ws/Zu7TSt
Answer for theme configuration problems