I've spent the whole morning, no kidding at least 4 hours, trying to understand why, after the hard reset following 4.3 FW upgrade of my F3, my phone was unable to register my F3 on Garmin Connect Mobile.
With the Hard Reset (due to the restarting loop) all data was lost so I first had to go through the main settings and the NAV points. Luckily all data depending on Garmin Connect are stored online and retransferred to the F3 via Garmin Express.
However, since the Wi-Fi and Bluetooth settings were also lost, I basically had to start ALL the configuration from scratch and I got jammed, literally, at trying to understand WHY the F3 was no longer visible on the GCM phone app (Samsung S3 Neo).
My ordeal is here.
There is definitely a bug in GCM right now and your phone might very often lose the WI-FI connection as you try to fix the issue. Without connection to GC, GCM can't operate so keep that in mind. It's not a problem of routers, wireless or internet connection (youtube all the way in the background here). So GCM messes up both the BT and WiFi.
If you find the authentication FAILS on GC it's because of this connection problem caused by either GCM or 4.3 or both (but I think it's just GCM that needs an update).
Unpair F3 with phone.
Clear data (all data) on GCM... you might as well uninstall and reinstall it but clear the data first.
Turn off and on both the cell phone and the F3 (keep BT off for the moment).
Check your Garmin Connect Dashboard. In my case, the watch was not being loaded in the widget and this rang the bell.
Unregister your F3 from your Garmin Account.
Turn on the F3 and connect it to Garmin Express. Follow the procedure to re-register the watch to your account. Garmin will mail you congratulating for your new Fenix 3 (worst purchase of the year needs an extra congratulation)
Turn on BT on phone and F3.
Pair F3 with phone.
Go to GCM on your phone and you should see the F3 in the devices list, not connected (yet), this comes from Garmin COnnect itself. Check GC dashboard and you'll see the brand new F3 on your devices widget.
Sync the F3 on the phone, this means set the F3 to PAIR again.
At this point GCM will crash and they will ask you if you want to send a report. Do it. Tell them how much you love them.
You will not believe it but when you open GCM again you'll see the F3 is now paired.
Head for the settings.
Turn off and on both the phone and the F3.
And it's done... at least here and in my case.
Summary:
If you see in the GCM synch details Requesting device identification file failed it's because GCM has messed its state on GC (proceed to remove F3 from your devices and reinstate it via Garmin Express).
If you see instead OTHER_FATAL it's because your CONNECTED F3 also needs to be in PAIRING mode (it's the same you do when you pair it with the phone, set it in pairing mode when the GCM is synching).
