Sometimes there are errors on pages that use the RICS Link application that can be resolved by restarting RICS Link.  To restart the RICS Link application:

1. Right click the RICS Link icon in your system tray
2. Click Exit
3. In your start menu, Search for Link 
4. Double click the Link application to start it
5. Refresh the RICS page by pressing CTRL+F5 on your keyboard
6. Try and upload again