Your shockwave_alpha.png is broken. It even crashed one of my image editing tools. I made simply a new one in Gimp with an alpha channel and replaced the one in your test level. The models aren't disappearing anymore. It seems that Gamestudio uses the broken PNG as if it were nontransparent so every model behind it gets culled away by the renderer.

Do you use several views with stages inside your project? Maybe the pointer to the render target is set to the wrong TargetMap when when your shader is being processed?