I have been away from Aerofly FS 2 for quite a while, so only yesterday I noticed the API the Wettergerät relies on now requires an API key. I updated the Wettergerät to be more helpful in situations like these, and added some instructions to the Wettergerät's documentation on how to get and supply an API key to the Wettergerät.
In any case you will need to
- download the latest version of the Wettergerät
- get an API key for your METAR REST service of choice
- and supply the key to the Wettergerät