I had some strange issues with the H2-DB. It was getting corrupted and nobody here could tell me how to fix so far. I deleted the whole installer directory in such cases and run the installer again. Than the examples worked just like shown here:
It must be a way to "destroy" the H2-DB and get errors like this. I keep searching but still have not found a way to reproduce/fix. Would be interesting if you ran in similar issues. Just give it a try with deleting and installing again and please post your results.
indeed I reinstalled all again and now tasks appear in the list. Things work as described.
At this point I don't know what is stable and what's not.