I'm not sure exactly what is causing that...
However, your repository is not on the Internet. Once you clone your repository from GitHub, then you have a local copy, and Eclipse should be working with that local copy. The only time Eclipse should need to use the internet is when you do a Push or a Pull -- that's when it needs to connect to GitHub to send/receive information.
Maybe Eclipse can't find your local repository. (Did you clone it onto the C: drive of a lab computer? Are you using your own computer?) (It would be helpful if you provided more details in your question!)
If necessary, you can try deleting your repository and re-cloning it again, and re-importing it into Eclipse. Or if you show me in person I may be able to suggest other ideas...
