This application has failed to start because nsdhelp.dll was not found.
However the problem was resolved within a few minutes. After a quick tweet I almost immediately got a reaction from IBM Champion Oliver Busse. To solve the problem the nsdhelp.dll file could be copied from another Domino environment 9 (or backup) to the new Domino installation. With this the problem was indeed solved and the Domino Server could be started without any problems.
What do we have a great community in which everyone helps each other. Amazing!