No luck here...
I tried 3 times.
When i hold sync button, the 1.6.8 "upgrade" show up, click on it, and that's write fail... i restart everything, seems ok, because, it1s write i have 1.6.8. on dji go.
than i put 1.5.7 on sd, restart everything, with hold sync. Dji go writes the same, the 1.6.8...