I wonder if other users receive the same error (GS Sport Travel Manage 1.4) when attempting to open a kml file or gpx:
Unknown file format, unable to open selected file
Thanks you, Juan
(SO: W7 64bits)
We follow the GPX standard, however, there are several customize version to cause incompatible problem.
GPSbabel is a popular conversion tool, you can use this to make it readable. Please download it from http://www.gpsbabel.org/
Or please send me your GPX file for checking.