I am currently using CityEngine 2014, attempting to import a .kmz file, and experiencing the same 'KML schema validation failed' and 'mesh creation failed: PRTX mesh violation: mesh must contain one face at least' warnings under the log. Specifically, the model imports without any of the textures for building facades and roofs. I have made numerous alterations to the texture paths in the .dae and .kml file (the textures are referenced in both, and this displays correctly on google maps/Earth).
I am posting a web-link to the kmz file open in Google Earth:
And a second link to download the .kmz file:
I have changed the .kmz file layout to ensure the texture paths in the .dae file and the .kml file match the location of the textures. Any help would be greatly appreciated.