DisconnectReasons

public static final int ENGINE_DETACHED = 2

Wallpaper service detached from the engine, which is now defunct. The watch face itself has no control over this. Usually in response a new InteractiveWatchFaceClient should be created (see WatchFaceControlClient.getOrCreateInteractiveWatchFaceClient).

public static final int ENGINE_DIED = 1

The underlying engine died, probably because the watch face was killed or crashed. Sometimes this is due to memory pressure and it's not the watch face's fault. Usually in response a new InteractiveWatchFaceClient should be created (see WatchFaceControlClient.getOrCreateInteractiveWatchFaceClient), however if this new client also disconnects due to ENGINE_DIED within a few seconds the watchface is probably bad and it's recommended to switch to a safe system default watch face.