There are a few possible reasons for this:
1. Every required field must be completed, otherwise, a warning message will be displayed.
2. Your session may have expired. Just close the window and restart your browser.
3. The command may not work because cookies are not enabled in your browser. If that's the case, you need to enable cookies. To find out how to enable cookies in your browser, click HERE.
4. Verify your internet connection. An active connection is required to validate the different form pages.
If you're still having trouble, contact the elves for support HERE and be sure to tell them what steps you've already taken.