Hi!
1- Be sure that GpxPatch.exe is located into your main Grand Prix 4 folder.
2- Launch GpxPatch.exe from this folder and look at the main GpxPatch tab : Startup/ Gpx Executable: gp4.exe must be selected.
If you can't solve it, I suggest you to uninstall GpxPatch and to reinstall it again with the last version: [
rsdi.home.xs4all.nl]
Suggestion: If you want a better or quick help, I suggest you to edit the title of your thread to precise your problem, like: " GPxPatch error at launch" or something related.
And don't forget to edit your title with the mention [ solved] when your problem is fixed to help people who could encounter the same problem than you. ... Just an advice, though
____________________________________________________________________________________________________________________________________________