What build is that and what CPU type?

It's Built 386 and CPU is Intel Xeon 2.8 GHz. We have 2 more servers with the same hardware and same built and they are working.

Well, some of us here might be very careful with verb working and build 386 (I'm not saying it's that bad, but there are newer build even they probably do not have any related issue to yours).

Try following - stop ALL services except those required to boot up the box and NW. See if NW runs there... if this is issue on the box which is identical to the others it has to be somehing specific to that box. After that add services back one by one.

Also, since there are several Win versions (3x) of each distribution check to make sure correct one was applied.

I think it's an other error. Now i have deleted all storage nodes and devices. When i'm installing them again in the networker-management the following message appears: storage node bdc is already registered as pdc. How can that be?? Hm, maybe the database of the networker is damaged!? I think i have to reinstall the whole backup-server.
What is the last built and where can i find it?

That's possible if your liases or NDS (hosts) is messed up OR you maybe use nsrauth which I would recommend to disable on both server and each storage node (after that you must restart NW services).

Latest build is 399.

I have reinstalled the whole backup-server and it's working. Now i have to inventory all volumes again...

You can use nsrjb -IIv -S to make it faster.

Thanks