You're all set now.
Your diagnostic is showing that your controller isn't connected to your players, which isn't really related to the issue others are experiencing here. Best start would be to make sure your players are on the network, and that your controller is still connected too. If you're still having issues, there are some great steps to take, but the update patch here isn't going to fix connection trouble, it's for an issue where the PLAYBAR only plays audio from some channels or sources, but not others.
Problem I have is I have an "all wired" 1Gb system. Prior to the upgrade, the mac app was high performing. After the 7.4 upgrade, the sonos app fails to connect to the system - no changes have been made aside from the 7.4 upgrade. Now, it takes several minutes after launching the desktop app before the sonos app "finds" my system. No other changes have been made, so it's not me or my internal system or Cat6 cabling.