The Marketplace Download does not work, what is going on?
As of the writing of this article there seems to be a bug with Roads and Paths on the Unreal 4 Marketplace.
This fix should be applicable to any other asset pack that is suffering from the same problem.
Please put in a ticket to request the project source files if this happens.
After attempting to add the asset pack to a project, the wrong results may look something like this:
How to add a GameTextures.com Asset pack to a project.
Make sure the main project folder of what is being import into is open. (MyBigFatTest is what I am using, aside from the name the project folder should look nearly identical)
Copy the unzipped contents of the RoadandPaths project into the destination project folder.
Delete the Roadsandpaths_4_20 project file
Open up the destination project and let the import process work its way through.