In setup, the step Allow screen access lists Accessibility as optional: “Optional. Puts windows back on the display after it restarts or reconnects, and enables shortcuts.” You can skip it and allow it later.

“Accessibility lets Second Display move windows. It never reads what is in them.”

What it’s for

  • Putting windows back on a display after it sleeps, restarts or reconnects. Move windows between displays
  • The ⌃⌥⌘ and arrow key shortcut that moves the front window to another display.
  • The brightness keys for the display under the pointer. Brightness

Without it, the picture works as usual, and these settings say “Needs Accessibility”.

Allow it

  1. In setup, click Open System Settings… next to Accessibility. Later, find the same row in Settings › Permissions.

  2. In System Settings › Privacy & Security › Accessibility, turn on Second Display.

  3. Go back to Second Display. The row says “Allowed”.

If Second Display is already on in the list but the row doesn’t say “Allowed”, turn it off and on again.

Settings › Permissions shows every permission Second Display uses on this Mac and where to change it.