[Solved] Clock is hanging in the clock app

Many thanks for the quick answer. I had "resetting without loading any code" tried before, but probably released BTN2 too fast. Now it finally worked. It took me a few tries to delete the apps, because somehow the bluetooth connection broke down often, for whatever reason. But now the clock works again! :)

Apart from the apps of the App loader I had only tried my own clock app, which was not set as default. But I had played around with the HID feature before.