Sorry, I don't know how to send you the file. Doesn't seem that I'm allowed to PM you yet. I probably need to write more in the forums:)
...but when I start the application it looks like this in the cmd window:
C:\Users\Reine\Downloads\LDraw2Sunflow_b>java -jar Ldraw2Sunflow.jar
aug 24, 2015 4:07:56 EM java.util.prefs.WindowsPreferences <init>
WARNING: Could not open/create prefs root node Software\JavaSoft\Prefs at root 0x80000002. Windows RegCreateKeyEx(...) returned error code 5.
aug 24, 2015 4:07:56 EM org.ldrawtosunflow.ui.Ldraw2Sunflow <init>
INFO: en_GB
Could it be a problem with localization?