@KodeZwerg: Thank you for your patience.
I implemented your function now and for the first time the job is done without problems, without error-message, without strange unit.
Now, you will ask: "Why did she hesitate to do so for one moment?"
Well, there are reasons, 2 of them:
1)
Once upon a time there was a rainy day, I did nothing special at all, nothing with the net, nothing with software, no browser, really nothing.
On this day my DNS-resolving was shot. It took me a while to find out about my connection problem at all.
My Win 7 ate my DNS-resolutioin. Somehow I repaired them. Long ago, I cannot remember any more how. My backup shall hold a file about.
To sum up: I rather would prefer a check without DNS-resolve needed.
2)
It is Microsoft. Those hated-by-me-guys have the best operating system and I use the stuff of them all they long, because it is grrr good. Never the less, I would prefer a solution without them. One day I will work on without them, yes. LibreOffice shelters me since long and the operating system will follow.
Here is a list of servers I would prefer to contact, but I do not know how. http://4.2.2.1 does not work.
https://sebastianhetzel.net/zuverlaessige-oeffentliche-dns-server/