From time to time programs can crash; QuickBooks, Sage and other programs experience this - usually displayed by the spinning progress wheel and the inability to click on anything. This is a problem with the program and not your hosted service.
Should this occur, please reboot your computer and wait 30 minutes before trying to reconnect to the hosted service. This will reset your session and you can resume working.
Please start a timer on your phone or other device; the 30-minute window is key for your session to expire and reset - if you connect earlier than 30 minutes, you will reconnect to the same crashed session and you will need to repeat the above.