A shortcut does nothing

The usual cause is that another app, or macOS itself, already uses that key combination. Re-record the shortcut in Preferences as something else. The toolbar always works in the meantime.

Check the menu bar

Click the pen in the menu bar. If the start/stop shortcut couldn’t be registered, the Start drawing item says so, for example ”(⌥⇧D unavailable)”.

Re-record the shortcut

1. Click the pen in the menu bar and choose Preferences…
2. Go to Shortcuts.
3. Click Record next to the action and press a new combination.

Preferences refuses a combination that’s already in use and tells you why:

• Already used by another PenLayer action. Two PenLayer actions can’t share a shortcut.
• Already taken by another app. Pick a different combination, or change the shortcut in the other app.

macOS can win without saying so

Some system shortcuts take priority over apps without reporting a clash. A shortcut can then register and still never fire. If a shortcut looks fine in Preferences but does nothing, record a different one.

Check when the shortcut is active

• Start / stop drawing (⌥⇧D) is claimed all the time, so it works whatever app is in front. Because PenLayer always holds it, another app that wants ⌥⇧D won’t get it while PenLayer is running.
• Undo, Redo and Clear the canvas only work while drawing is on.
• Single keys such as 1, [ and S only reach PenLayer once the canvas has focus. Click on the screen once after you start drawing.

See Keyboard shortcuts for the full list.