If scanning worked before a Windows update:

Windows disables "guest access" by default to prevent unauthorized users from accessing shared folders. Your printer is likely treated as a guest.

You likely need professional help if:

is a frustrating roadblock that typically appears on network-connected Xerox WorkCentre and VersaLink multifunction printers (MFPs). When this error flashes on your control panel or computer screen, your scanning workflow grinds to a halt.