When I start the game, and after every logo and cut-scene in the beginning, there's this error message. It disappears after some five clicks, but still really annoying.
Searching this forum hasn't brought up anything...

Error is something about " 'Direct3DCreate9Ex' hasn't been found in 'd3d9.dll' " (in German)

Any help?

Make sure all older components of DirectX9 are present on your system by installing this:
http://www.microsoft.com/en-us/download/details.aspx?id=8109
Run the file and extract the content to a separate folder. Then use dxsetup.exe to start the installation.

i tried doing this myself and it didn't fix it, also i cant change the resolution of the game

Ran into the same problem. I also tried the above without success and googled some solutions, but I'm not getting it to work :/

Thanks for the answer so far.

Funny thing is, once I'm in the game, everything works (also changing the resolution). But getting there is just plain annoying.

Tried the DX installing, also, without success...

Have you already tried setting different compatibility modes and running the game as administrator?
Right-click the game's shortcut and select Properties. On the Compatibility tab you can set the mode and tick the option to run it as an administrator.

Sadly it didn't help me at all. Well, aside from the popup the game seems to run perfectly fine anyway. It's a minor annoyance, really, so I'm probably gonna live with it.

Edit: I just noticed that I *need* to launch the game as administrator, though. Not all of the shortcuts do that automatically and when I try to launch the game through one of those the game simply won't launch. Wouldn't have thought of trying "launch as administrator" without your post, so thanks for that.

Perfect, thank you!