How to resolve this error.

How to resolve this error.
ruby - 1.9.2 -p180
rails - 3.0.9

I am upgrading my rails 2.3.11 and ruby 1.8.7 application to these
latest versions and when i tried to run server it gives me this error.

Value assigned to config.time_zone not recognized.Run "rake -D time"

and when i am trying to run any kind of rake command it gives me

no such file to load -- config/environment