Error code 15106 in QuickBooks Desktop typically occurs when an internet connection issue prevents QuickBooks from reaching the update servers. First, try switching to a different, stable internet connection and retry updating. If that doesn't work, temporarily disable any firewall, antivirus software or VPN that may block access to QuickBooks servers during updates. Run the QuickBooks File Doctor tool or speak with QuickBooks support just dial us at +1(855)-738-0359.if the problem doesn't go away if you do any of those things.