How to fix a faulty engine model in TS12?

So, I was downloading some models (Camscott's RWS Donald and Douglas) to put into TS12, and I downloaded the missing dependencies from the Download Station, but it says the model is faulty.
I had a look at the list of errors and warnings, and the only one that pops up is:

Error: Tag 'asset-filename' in the container 'traincar' is obsolete.
Does anyone know how to fix this? Any help would be much appreciated.
You need to contact the help desk to register your copy of TS12 as forum members are often reluctant to help anyone who has an empty siding track beside their username.
Now as to the problem you are having what you need to do is open the config file and entirely delete the asset-filename tag line. Once that's done save and exit and commit your changes. If that was the only error you should now have a functional locomotive