There are a few other useful tools in the PlayUp Toolbar to help you troubleshoot potential problems:
Unless specifically set, game engines render only the front face of a mesh by default. However, SketchUp allows you to see and texture both the front and the back of a face. While it may look right in SketchUp, it will appear to be an invisible face in a game engine. This icon toggles a style that helps you identify what faces will show (in dark gray) and what will be invicible (in bright green). Simply click the icon again to return to your original style.
Some engines have a limit to the number of vertices that a mesh can contain. Select a group or component to check how many vertices it contains. It will calculate the vertices of all nested groups and components as well.
Tips to Avoid Common Pitfalls
Put everything that you want to export in groups or components. Rogue geometry will not be processed by PlayUp Tools during the export process.
Paint textures and colors directly on the faces. In SketchUp you can use the fill tool to paint all of the default textures on a component or group. However, it doesn't actually paint the individual faces when you do this-- but rather sets the default for the entity. During export, PlayUp looks at the individual faces for the material information, so any group or component material that has been applied will be ignored.
Ensure that you are painting the front face as that is what game engines render. Use the Check Normals tool to toggle a view that allows you to quickly check for problem areas.
Do not shear or distort textures intended for export. SketchUp gives you the versatility to shear and distort textures on a face. Game engines do not have the same versatility resulting in some potentially strange outcomes.
Are your textures still not being generated? If your textures are not being generated after following the tips above, install the Visual C++ Redistributable Packages for Visual Studio 2013 as you may be missing a required DLL for the texture converter.