What does Windows error code 1419 (ERROR_HOTKEY_NOT_REGISTERED) mean?

ERROR_HOTKEY_NOT_REGISTERED

The hot key is not registered

UnregisterHotKey releases a hot key previously registered by the calling thread. The pair of window association and identifier is part of registration bookkeeping; the key combination alone is not the removal handle.

A common bug is unregistering after the owning window has changed, using a different ID from the one passed to RegisterHotKey, or executing cleanup twice. Thread-associated hot keys use a NULL hWnd, which must be mirrored when unregistering.

What to check

• Store the registration ID and associated HWND or NULL as one record.
• Mark successful registration explicitly; do not infer it from configuration intent.
• Make shutdown cleanup idempotent so the same registration is not removed twice.
• When a window is recreated, unregister the old binding and register against the new lifetime deliberately.

The opposite condition, ERROR_HOTKEY_ALREADY_REGISTERED, is a collision while claiming a key combination.

References

• Microsoft: RegisterHotKey
• Microsoft: UnregisterHotKey