I tried to make routes in MyRouteApp, saved them as gpx, converted these with itn-converter, copied them to the iterinary directory of Sygic. When I start the route sygic (15.2) did crash during the calculation.
Then I save the route in MyRouteApp in tomtom-format (.itn), converted and copied it. Now I can start the route and it works
in may case: starting with a gpx-route did not work but starting with a itn-route worked great.