Yep, it is Basecamp. I copied the file to my PC, reset the Oregon, and moved the file back. No good. I then did a factory reset on the Oregon, and regenerated a GPX file, and put that on the Oregon. I am getting that error again. I am really starting to think I have an issue with the Oregon itself... My two last "spare" SD cards are 32GB & 128GB, so I think those will introduce new issues. I am incredibly confused now. The Oregon now has NO maps on it, as far as it can tell. But I the the Midwest TOPO installed on the SD card in the unit.