I made a 3d model in Blender and I used an addon to export it to W3D format. Then I opened finalbig.exe and extracted it to the ART\W3D\ folder of Command and Conquers Generals: Shockwave v 1.2. The file isn't particularly big, it's 345 kb, when I've seen there is an original W3D file which is 311 kb. I know I'm changing the reference to the 3d model in the right place of the .ini file, because in the first attempt I unsuccessfully loaded the model to the ART\W3D\ folder and the result was the vehicle (aircraft) existed and fired and everything but it was invisible.
Any ideas what can it be that's making the game crashing? Does the W3D file needs something else to work, perhaps I have to move image textures in png format somewhere or something?