I had a customer write earlier saying when he starts the game he gets the following error:

Error E155, Can't open mouse device.

I can't find this in the manual anywhere and there's only one thread here in the forum referencing it, but the answer is to check the manual, so, uhmmm...

Anyone know what could be causing this?

I think it happens when either the mouse is not connected, or DirectX is not installed.

Weird, the customer says the mouse is installed and works fine with everything else on his system. I'm not really sure what to make of this. Thanks for the comment.

Maybe its a non-standard mouse, like a trackball, touchpad, or one that requires a weird
driver, like some of the REALLY OLD logitech mice.
I havent seen this in a long time though...

Whatever it is, it looks to NOT be DirectX compatible, and thats a problem.
Does the user have any other "real" Directx9 games to test it with?