Invisible Loco's from the DLS

I'm using TRS2004, and just got a Ticket for the download station, (A bit behind schedule I know), but after attempting to download some Locomotives, i get this bug where they don't appear in game. It seems that this problem only affects re-skins, as some loco's work, but the custom liveries don't appear in the 'railyard' viewer. They cannot be placed in the surveyor either. I have no missing dependencies and paintshed installed. Can anyone help? Would be very grateful for a solution.

theothertwin

Locomotives and other assets intended for newer versions of TRAINZ may not work or be viewable in TRS2004.

No, I know they are for TRS2004, I can't download anything newer, and i have double checked to make sure that this isn't the case. I updated my TRS2004 to SP4 and that has solved a couple of issues. Only some rolling stock are invisible now.