In some cases, you will run your web connector and it will say authentication failed. If you click the blue link beneath the error, you will see this message:
If you run QuickBooks on a remote machine, like RightNetworks, this error means that Windows Server auto-logged-out a user and closed QuickBooks for them. The server is still holding the file lock on the QuickBooks company file. Windows will automatically release the file lock in thirty to sixty minutes.
If this error message persists, contact your hosting provider and ask them to unlock the file. Run your web connector.