I am extremely grateful for this advice, shutting down Teamviewer made my nightmare disappear!
As a beginner, you always look for own mistakes, errors, misunderstandings in the first place. I watched several hours of video tutorials, but whenever they came to the point of importing an apt.dat file, I felt desperate because I could not discover what the guys must have done different than myself... Never got the airports loading... WED always kept shutting down without any comment or message...
Imagine my relief now after finding this post about a funny, strange and weird incompatibility with some background process of an application totalls unrelated to WED...
Wish everybody a good night,
Charlie