Why is Germany (once again) in an Immigration Crisis?

Images of the German warm welcome of refugees during the migrant crisis of 2015 travelled the world and inspired more refugees to choose Germany as their destination country. Now that a decade has passed and the number of asylum seekers in Europe is almost back to the level of 2015, what can we say about the success of Germany's handling of refugees during the first migrant crisis? And how will this second crisis be different?