Win 10 mail app sync error 0x86000c09

To summarize, I am no longer able to sync messages from Exchange

2 Win 10 devices going to a GoDaddy hosted Exchange account

Both were working

Performed a clean install on my Surface Pro

Will not DL or sync email messages but empty folders show up

I have removed device registration using OWA/options and added account and reboot many times

I removed my account from second device and now that one will not sync

Active Sync test connectivity test is ok

Log from OWA shows the following

Command_WorkerThread_Exception :
--- Exception start ---
Exception type: System.InvalidOperationException
Exception message: Operation is not valid due to the current state of the object.

Can anyone suggest additional steps I can take to resolve this issue? Outlook 2013 works fine from both devices but I need a more tablet friendly app on the Surface Pro.




I had encountered the same issue last night when I booted my PC up. I also chatted to two technicians and both did not resolve the problem, so I decided to do some investigation myself.

I managed to resolve the error myself.

The Mail app on Windows 10 was using my Hotmail account, so I decided to log into Outlook with that account via the web interface. Once there I went to Options -> General -> Mobile Devices (the left hand side task bar). There I could see a number of 'mobile devices' that were synchronized. If you select the 'Detail' icon you can get further details about the device that it is synchronizing with or synchronized. I then selected the 'Remove' icon on the 'Device' that was having issues syncing. After it is processed and I refreshed using the 'Refresh' icon, I proceeded to re-sync using the Mail app on Windows 10. It properly synchronized and a new 'mobile device' appeared on the list.

This worked for me and may work for you. However I am unsure of the full consequences of the 'Remove' feature, so use at your own risk. I hope if you use this method above that it works, as it worked for me.

Kind regards,


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Question Info

Last updated September 4, 2019 Views 15,471 Applies to: