Dan sent me his .sua file and it's a valid .sua, works in my ClearNav PC sim. I suspect the issue has to do with his usb. reply sent...

It's rarely required, but if you ever lose your CN usb or need to rebuild it for some reason, the usb contents including the updater are archived on the CN downloads page. Note that the usb updaters for CN1 and CN2 are different (and so labelled).

best regards,

Evan Ludeman