The most common reason for this error during a new scanner installation is failure to remove/unlock the shipping lock.  The shipping lock is installed at the factory to prevent the scanbar from moving around and being damaged during shipping.  Follow the instructions in the user manual or the installation guides for setting up your scanner.  Do not lose the lock!  You must reinstall the lock anytime you ship the scanner to another location to prevent possible damage to the scanner.  The other reason for this error message is either a jammed scanbar or a component failure.  If you have removed\unlocked the shipping lock and continue to receive this error message then please call technical support at (800)626-4686, option 2 for further assistance.