Garmin GDB -> GPX Conversion fail

[VolkerB]

Garmin GDB (aka. Garmin GPS Database Version 3 as produced by latest version of MapSource) file conversion to GPX does not seem to work.
I ran

Code:

java -jar RouteConverterCmdLine.jar test.gdb Gpx10Format test.gpx

and received a basically empty GPX file. Source and result file plus console dump attached. Using Java 8 Update 91 on Win7x64.

Code:

c:\temp>java -version
java version "1.8.0_91"
Java(TM) SE Runtime Environment (build 1.8.0_91-b14)
Java HotSpot(TM) 64-Bit Server VM (build 25.91-b14, mixed mode)