Hi,
My dndclient crashed on launch, just after choosing server. I am running in Windows 7, and the error is:

Problem Event Name: APPCRASH
...
Fault Module Name: nvdxgiwrap.dll
...

Looking in forums of other games, the problem may be that the video card was not working properly. This problem started in my computer after an automatic Windows update (previously no problem) the day I am writing this.

My solution was to update the video card driver (NVIDIA GeForce GT 540M in my case), and then dndclient worked again. I write just in case someone else has the same problem. Maybe my solution also works for him/her.