This is mostly a maintenance update before the larger upcoming 3.12 release. Here are the main highlights; see the release notes for a full list of changes.
Multiplayer fix for macOS
Stardew Valley got a small update to fix multiplayer on macOS, and SMAPI 3.11 adds an equivalent fix for mod players. Special thanks to Mr. Podunkian from the Stardew Valley team for his help with the SMAPI changes!
'Furniture list changed' event
Detecting problem apps
Some apps (like MSI Afterburner and RivaTuner) often cause difficult-to-troubleshoot player issues. SMAPI now detects those apps and logs a message with their details to simplify troubleshooting.
Other improvements and fixes
See the release notes for a full list!