I see many of the files I've imported into 2012 give the warning that the thumbnail container is missing. What is it and where does it go? What does one type into the config file and where? Thanks in anticipation. Cheers
Then add a small image file named temp-thumb.tga in the same folder where the config file is located. That will prevent the warnig from showing although that is more for the look since warnings are only for you. Trainz still accepts an object if it only has a warning. That might change in the future so it is a good habit to always add one.
I just encountered the same problem importing a route from 10 - 12. Did a quick search on the forum and unlike most occasions, the first result was this thread! Most fortuitous advice indeed. Got my problem fixed.