This error indicates the FAWeb/NetClassroom server time may be out of sync.

To see the last successful time sync:
  1. On the server open a command prompt.
  2. In the command prompt type W32TM /QUERY /STATUS
To synchronize the clock with the domain time:
  1. On the server open a command prompt.
  2. In the command prompt type NET TIME /DOMAIN
To synchronize the clock with a specific computer:
  1. On the server open a command prompt.
  2. In the command prompt type NET TIME \\<machinename> /SET /Y or NET TIME \\<ip address> /SET /Y