•When you open a migrated file in AC20, the setting for the new Single Window environment will be off. To activate the new single-window environment, go to Options > Work Environment > Legacy Window Mode and toggle it off.
Newly created AC20 files on Mac will use the new Single Window environment.
•The palettes and windows of migrated files will be undocked to begin with. However, palettes and windows are now dockable in the Mac environment.