Try opening the same url/challenge within Firefox.. sometimes if you're confident your code is correct reloading the page in another browser may solve the bug.. Make sure to report this to Codecademy as well 
If this doesn't work I'm afraid either a) post your code so I can check it's validity.. and b) report and wait for codecademy to fix.. If this is the case make sure to not only use the 'Report a Bug' feature but also take a screenshot and post it within this forum..
Also as a closing note check the Troubleshooting thread and see if you've ticked all the boxes 
