How to solve "Failed to open a connection to the device (-21345)" when trying to scan using…

Feb 24, 2021 · 3 min read · After trying to scan from my Brother Printer MFC-J995DW using my Mac under Catalina, I faced this problem and found a solution, related to IPV6 address conflicting with the AirPrint scanning feature. So here is a small step by step to help you resolv...