When I got on to trainz most of my locomotives have missing dependencies, when I thought that I had them all, why? Also some of my locomotives are missing, but it says it is in the game.
The first thing that I would do in that situation would be to perform a DBR (database repair).
If you are not sure how to do that then..
from the Trainz Launcher widow, open up the Developer menu
select the option Rebuild Database
Depending on the size of your database this could take a few minutes. After it completes, close the Launcher and restart Trainz. Open Content Manager and check the locos again.
No guarantees but that *may* fix the issue. If not then more drastic measures could be needed.