This may help... (It's fixed my Turbostar errors) - this will only work though if the error is something like 'xxxxx.texture is missing or could not be loaded for (some path)/xxxx.im' (replace the xs with the actual file names)
WARNING: Some textures on the affected asset may not appear correctly after doing this, so make a backup of the assets in question first just in case.
1.Download PEVSofts PM2IM software and install it. If using Windows Vista/7 the tool must be run in admin mode.
2.Open the affected item(s) for edit.
3.Open PM2IM.
4.In the Options menu, tick Auto Convert and Strip Textures (you can tick Close on Done if you only have 1 to do).
5.Click Open in the File menu of PM2IM.
6.When the Open box appears, you will need to find the Trainz installation folder then go into Editing. Once you are in the editing folder, open the folder for the asset you are using the tool on, then open the .im file mentioned in Content Manager. Be aware that PM2IM will overwrite the existing .IM file, so make sure you have a backup before using the PM2IM tool on it.
7.Re-commit the asset (once you have closed PM2IM)
Hopefully this should fix the faulty aspect.
Shane
(Sorry about bumping the thread though, but I have only done so to give some important information - the information given here can also be used with non-railwaves assets).
If anyone is confused on any aspect of this post, please let me know.