Original User: dougjcI've managed to figure this out with a bit of trial and error.Its all down to the ArcGIS debugging tools available in the JavaConfigTool. In particular the "Create Console" option, with my setup when I have this checked and I try and run any custom geoprocessing tool (even something straight out of the wizard) the whole thing crashes. But once you disable it the geoprocessing tool runs fine.Going to try and raise this as a defect with ESRI.