Thanks jcl (not only for your answers but for the strategies in general).
Because nothing happened last week until the weekend I thought that nothing is lost in checking what happens when I restart my laptop and yes, it all started from scratch again.

So far I read the main topics and programming instructions of the manual and checked http://zorro-project.com/manual/en/zsystems.htm .
I figured out that Z12 for example brings up some errors when trading with a demo account with global prime, which I first did set up with a leverage of only 1 (to simulate a cautious first trading).
So I have to learn more about them, because my suspicion is that Z8 needs a leverage of at least 2 and Z1,2 or 12 (and maybe also the others) a leverage of at least 200.
Someone told me NOT to play around with those leverages because it could be dangerous, so I won't, and whilst I experience how to run your Z strategies I of course will learn to write my own one.

Is there some more information to be found on the strategies, the meaning of the errors, and what happens in case a broker doesn't provide all currencies normally used by a strategy ?