Garmin Express requires Authentification and does not upload (new problem)

FYI, partially solved.
I found the data in C:\ProgramData\Garmin\CoreService\Devices\3860252604\Sync\FIT_TYPE_4
A FIT file was there - without the .FIT extension. I added the .FIT extension and was able to upload manually into GC.

But the main issue (why is GE requiring suddenly an authentification) remains...

2nd getting this as well. not even trying to upload activites, just change data values on the garmin. I reinstalled the device and as part of that you have to login, so it's literally a new local account for garmin express and it still has a pop up 're-authentication required' which is accepted but then immediately pops up again. I have a directory C:\ProgramData\Garmin\CoreService\Devices\3860252604\Sync\FIT_TYPE_4 which has loads of items in from yesterday. I also have a directory C:\ProgramData\Garmin\CoreService\Devices\3860252604\Sync\FIT_TYPE_9 I have a single file in here from today i rename this with a .fit ending and try the garmin express 'install/synch' again and get the same re-authentication pop up. The re-synch creates a new file in the C:\ProgramData\Garmin\CoreService\Devices\3860252604\Sync\FIT_TYPE_9 directory that again has no ending.

I have a seperate directory C:\ProgramData\Garmin\GarminConnect\Forerunner 310XT-3631190379\FIT_TYPE_9 which has an old file from months ago, same device and that DOES have a .fit ending.

I have no updates needed from the Garmin\Logs

***Running scheduled Express Update task
Express Path: C:\Program Files (x86)\Garmin\Express\Express.exe
Express version: 4.0.19.0
Sending application update request
No required updates found. Exiting. **
[/I]

From the Tray_2015-06-03.log the synch appears ok
***
Tray - Opening channel to subscription service.
Tray - Successfully opened channel to ISubscriptionService.
Display permissions set to: False
Tray - Successfully opened channel to IDeviceService.
***

Heres the FaultException from this morning, although I can't replicate this.
****
09:20:24.8576 | 1 | I | Device Registration Successful!
09:22:40.8652 | 1 | W | Error syncing device.
System.ServiceModel.FaultException`1[Garmin.Omt.Service.Faults.ServiceFault]: The creator of this fault did not specify a Reason. (Fault Detail is equal to Garmin.Omt.Service.Faults.ServiceFault). at System.ServiceModel.Channels.ServiceChannel.HandleReply(ProxyOperationRuntime operation, ProxyRpc& rpc)
at System.ServiceModel.Channels.ServiceChannel.EndCall(String action, Object[] outs, IAsyncResult result)
at System.ServiceModel.Channels.ServiceChannelProxy.TaskCreator.<>c__DisplayClass2.<CreateTask>b__1(IAsyncResult asyncResult)
at System.Threading.Tasks.TaskFactory`1.FromAsyncCoreLogic(IAsyncResult iar, Func`2 endFunction, Action`1 endAction, Task`1 promise, Boolean requiresSynchronization)
09:22:40.8902 | 1 | W | Failed to get device name for 3631190379 from connect.
*****

So I have removed the device
*****
ANT background task cancelled.
Device retrieval took 8 ms.
GetDriveInfoOperation_3631190379 setting phase to WaitingForResource.
GetDriveInfoOperation_3631190379 Reporting phase WaitingForResource.
GetDriveInfoOperation_3631190379 setting phase to Finalizing.
GetDriveInfoOperation_3631190379 Reporting phase Finalizing.
Removing operation Garmin.Omt.Service.Operation.FileTransfer.GetDriveInfoOperation from queue.
**********

re-added
****
SearchForDevices method from Garmin process acquired ANT host.
Device retrieval took 12 ms.
ANTFS_HostChannel did not receive an accepted response.

Accepted ANTFS_HostChannel response: ANTFS.Response.ConnectPass
SearchForDevices method from Garmin process released ANT host.
Found Unit ID 3631190379, Device Type 1018, Manufacturer 1, PairingEnabled True

*****
THEN THE FIRST EXCEPTION
*******
Failed to get matches.
System.ServiceModel.FaultException`1[Garmin.Omt.Service.Faults.UnauthorizedFault]: The creator of this fault did not specify a Reason. (Fault Detail is equal to Garmin.Omt.Service.Faults.UnauthorizedFault). at Garmin.Omt.Service.Operation.Sync.Upload.SyncUploadOperation.<GetMatchsForIds>d__4e.MoveNext()

THEN ANOTHER
**********
An exception occured that is getting sent to the client.
System.ServiceModel.FaultException`1[Garmin.Omt.Service.Faults.UnauthorizedFault]: The creator of this fault did not specify a Reason. (Fault Detail is equal to Garmin.Omt.Service.Faults.UnauthorizedFault). at System.ServiceModel.Dispatcher.TaskMethodInvoker.InvokeEnd(Object instance, Object[]& outputs, IAsyncResult result)
at System.ServiceModel.Dispatcher.DispatchOperationRuntime.InvokeEnd(MessageRpc& rpc)
at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage7(MessageRpc& rpc)
at System.ServiceModel.Dispatcher.MessageRpc.Process(Boolean isOperationContextSet)

and finally when I try and upload a course i get this

****
An exception occured that is getting sent to the client.
System.ServiceModel.FaultException`1[Garmin.Omt.Service.Faults.UnauthorizedFault]: The creator of this fault did not specify a Reason. (Fault Detail is equal to Garmin.Omt.Service.Faults.UnauthorizedFault). at System.ServiceModel.Dispatcher.TaskMethodInvoker.InvokeEnd(Object instance, Object[]& outputs, IAsyncResult result)
at System.ServiceModel.Dispatcher.DispatchOperationRuntime.InvokeEnd(MessageRpc& rpc)
at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage7(MessageRpc& rpc)
at System.ServiceModel.Dispatcher.MessageRpc.Process(Boolean isOperationContextSet)***


seriously why I am having to go through application logs just to synch my device.

TRICKSOFMIND

Sorry for any inconvenience this caused. What seems to be happening is the 310XT had some corruption on it. When the device created a bad file it got stuck in the pending "sync" folder on your computer. Now this does not mean there was anything wrong with the particular file as you noted you were able to manually upload the file to Garmin Connect. This means that Express was unable to determine what happened to the file and Express got stuck in it's communication to Garmin Connect. There is currently a ticket open on this issue. If the re authentication issue comes up clearing the sync folder can correct this. You noted the file path of the pending sync folder. The information on the file path can be found in the FAQ: Where do my activities go on the computer before they are uploaded to Garmin Connect?

Mike

I have a 610 and have the same problem. It apparently transfers the data from my device and then says 're-authentication required'. I've done that and nothing changes...

Please help! I need my data and have a half marathon on Sunday which I need the data for.

Thanks

Links working for me.

Had had the same issue since yesterday, but I got it in the end.
My 910xt could not upload two activities (yesterday's and today's), always showing reauthentication popup. I removed every old activity from the device, apart from these two. I was trying forced upload ([Mode]->History->Tansfer all) and nothing.
What I did was: I stopped Garmin Express. Then I removed every file from every subdirectory of C:\ProgramData\Garmin\CoreService\Devices\<unit ID>\Sync, leaving only empty directories. Then I again forced upload of activities. Finally I started Garmin Express and my activies got synced.

Have you lost all of your previous data now?

Looks like I did not lose anything accidently. All activities are in garmin connect. Of course I removed almost all activities from the watch, before performing this brute sync. This step may not have been needed, but syncing 6 month os history took too long. I left only two recent ones, that caused problems. These got synced. New training done after that also got synced. Looks good from my side.

sync doesn't work

I have a 910 and installed a software update on Wednesday. Since then no sync has worked. I had a number of different errors one of which was that I needed to log in again because Garmin Express couldn't authenticate etc.
I emptied the sync folders as suggested but no luck.
Any further ideas how to resolve the issue?
Thank you for your help!