What is a Nebula Assertion error?

The game was running fine until I started wandering around the forest at the Blood Mountain. All of a sudden I'm getting dropped out to desktop with a:

Nebula Assertion Error: nD3D9: begin pass - fail on effect.

Anyone know what's the cause and perhaps a fix? Maybe I should check for graphic driver updates…?? Been a couple of months now.

The 3D engine running the game is called 'Nebula Engine', so it is a failed assertion of the 3D engine. An assertion is a statement by the programmer about some state of the program or its variables that the programmer wants to be true (for the sake of correct behaviour). Assertions are helpful for bugchecking and bugfixing.

So much for the background knowledge. I can't help you with that particular assertion: Post your problem on the official forums: http://forum.dtp-entertainment.com/viewforum.php?f=188

Thanks. I just updated my nvidia drivers and did a windows update, but that didn't help. It's weird the way the whole game was running fine, and then just in the Blood Mt forest, I get dropped out ever ten minuts.

Originally Posted by CarcusRex
Thanks. I just updated my nvidia drivers and did a windows update, but that didn't help.

Oh… Sorry. When I mentioned the 3D engine I did not meant to imply that you should update your graphics card drivers or your OS.
On the other hand, updating this stuff never hurts.

D3D is a part of DirectX. Drakensang is very sensitive towards outdated drivers and not 100% correct DirectX installations.

I suggest you install the latest DirectX version. The correct, altough sligthly annoying, way to do it properly is:
1. download a full install version of the latest DirectX. Extract it to a directory, abort the installation.
2. switch off your PC, unplug your internet connection
3. boot the PC, deactivate both virus scanner and firewall (if it's different to the internal Windows firewall).
4. install DirectX
5. get everything going again.

If this doesn't help you have a problem.

In case anybody else is having this problem, I would suggest against upgrading ATI drivers to the 9 series. Those were causing no end of trouble on my computer until I rolled them back to the last 8 series driver, which is now running with 100% reliability.

I was getting that error too when trying to save the game in one part of some caves (think under dwarf city) but I have NVidia so I think it's just a generic error message. In my case I solved it by moving well away from that area of the caves, then I could save fine.