thanks a lot for your help.
In the meantime, I made some progress.
It seems indeed that the LE5 license was not properly re-activated. Apperently, there is a bug in the eLicenser Control, and Steinberg provides a complicated fix by installing an additional helper software. I thought that this helper software was only needed when I want to install the old LE5 version, but is was also needed to properly re-activate the LE5 license.
So I was able to upgrade the license to a proper Elements 11 license which is also properly activated. This is shown in the eLCC, as well as in the Steinberg portal. So this looks good. (it seems I cannot attach anything to this post).
However, I was not able to install Elements 11 with the original Download Access Code. Apperently, the Installer is still expecting an LE 5 license to be upgraded, whereas I have already activated a full Elements 11 license.
Since I had to get some things done, I have now installed a trial version. I was hoping that I can simply assign my Elements 11 license with the installed trial version and that’s it. But it is not clear how to do that. Can you help me with this final step?
Another small question: with the trial version, I made a mixdown (I tried both mp3 and wav). But I can’t open this with any player. Is this a limitation of the trial version?
Edit: It seems that the expert works find.
But it seems that I cannot play ANY audio file with ANY player, while Cubase is running. Strange. As soon as I close Steinberg, I can play the exported file.