You should Clear the Blueprint Cache after installing addons

[Bob Artim]

When you install an addon, usually it come with a Blueprint.pak file. This is like an index of the files in the addon. However these might not contain all the correct info if you havemore than 1 of the same thing. So the best thing to do after you install an addon is too close Railworks completely, even the launching screen. Start it back up and go to the Tools and Docs tab and press the Clear Cache button. Then when you run RW it rebuilds the pak files it needs.