Try Compatibility Mode
I'm assuming that you are running TS2010?
If the text against an item of rolling stock is shown in red it means that Content Manager has flagged it as "faulty".
If you want to use faulty items, try using Compatibility Mode (go into the Main Menu at the top left of screen, then Options/Video Settings).
You will have to exit and then re-enter TS2010 to activate this change.
You will then find that most (but not all) faulty assets can now be used in the game. Some say running in Compatibility Mode degrades performance. I've yet to be convinced that there is any significant penalty.
Phil