On 11 June, Norwegian ferried an empty Boeing 737 MAX 8 (SE-RTB) on flight DY8922 from Malaga, Spain to Stockholm Arlanda, Sweden. Uneventfully and at an altitude of 20,000 feet, the aircraft – banned for commercial use since 90 days – continued its positioning flight above Spain and France.
The Boeing 737 MAX 8, however, was not allowed to enter German airspace. The aircraft entered a holding pattern between the cities of Metz and Nancy before diverting to Châlons Vatry Airport, near Paris. Currently, the aircraft is still on the ground in France.
In fact, Deutsche Flugsicherung, the organisation in charge of air safety in Germany, forbids the overfly of Germany by 737 MAX 8 and 9 aircraft. The prohibition has been recently extended until 8 September. Norwegian should have known that!

The Boeing 737 MAX aircraft has been grounded since …. (count up timer)
The Norwegian 737 MAX 8 is finally able to reach Stockholm, after taking a detour around German airspace.
https://www.flightradar24.com/NAX2PC/20f8cb2f