Must have Mac software for Garmin. in Getting started Posted May 21, 2007 Okay, a little help, if someone could... I'm trying to run Mac SimpleGPS, but it tells me that "there is no default application to open the document 'Mac SimpleGPS.'" I'm pretty sure that the problem is that it shouldn't be a document, but I really don't know. I'll admit that I'm (effectively) pretty new to Macs, since I haven't seriously used one since the original ones came out in the 90's. Any thoughts? What are you doing when you get that message, "there is no default application to open the document 'Mac SimpleGPS.'"? I am wondering if you have set a default application for .GPX files. Try this... Select (highlight/click on once) the .GPX file (presumably a gc.com Pocket Query file, such as '1072256.gpx'). Press the 'Command(Apple)' & 'i' keys at same time... a small window titled "(filename.gpx) Info" will open. Go to "Open with:" section of the small window, and in the drop down box Select "Mac SimpleGPS" (presumably from the Applications folder). Then click on "Change All", and all .GPX files will be opened with Mac SimpleGPS (I am using version 1.7b). If you decide to change the default application to GPSBabel, or other, use the same steps but select the different application. I've been using Macs (and Windows PC's) since the early days (after machine language, and DOS). I am happy to help... send a message through my gc.com profile if needed.