Typically, this kind of message appears due to a lost Internet connection. If you are using a wireless connection, try plugging your computer into the router with a cable. If this works, stay connected until you have finished uploading your decisions.
If your machine uses a firewall, locate the firewall program and adjust the settings to permit Excel® to communicate with the web.
You can use the web version of the software. Click the Downloads link, select Rehearsal or Capstone then click the Web Spreadsheet link.
Apple users with Office® 2008 will need to use Web Spreadsheet.
An extreme solution sometimes involves reinstalling Excel®. Some of the features will function properly if a complete Excel® install is performed.
See the FAQ How can I permit Excel® to communicate to the Internet through Norton or McAfee firewalls?