Yet another -530 client not found error in Professional Posted yesterday at 08:11 PM · Report reply Magnificent investigation, MrPete! All machines on my LAN are Macs, and to my knowledge I don't have a network security system—not to mention VMware (for which the -530 problem was discussed starting in a 2017 thread). I don't have a firewall on my LAN's FiOS "gateway", and the firewall is disabled on my MacBook Pro. As a result of your investigation I'm now wondering if my "gateway", which is a Verizon G1100 which also functions as my router, uses pfSense (or its fork OPNsense) code. Almost a year ago I ran a test which temporarily connected my MBP "client" to my Mac Pro "backup server" so that it was "upstream" from my "gateway". However I didn't think of disconnecting the "gateway" until I had disassembled the test setup, and the connection probably wouldn't have worked without it. However my original -530 problems, which started on 30 January 2017 when I still had DSL instead of FiOS, occurred only when I booted the "backup server" after the scheduled time for the backup script and the script ran immediately—so I thought the bug was caused by uncoordinated startup in the Retrospect Engine.