Hi Umberto!
I have the latest v1.9 as well as the new vehicle download you recommended at the same time. I have the textures for the new de-icers so I assumed all was well. When I used GSX for deboarding at VYYY today, the conveyor trucks and the ground crew were all black -- no texture or color. This was at Gate G9 and I was using PMDG NGX. I am including a jpg as well as my modified AFCAD file. This is a default airport and though I did not apply latest upgrade yet, there should have been no effect on VYYY, should there have been?
Craig