Errors persisting in windows 10 even after clean install. Help needed!

I've been getting "The Sync Host_Session1 service terminated unexpectedly" and it seems to be related to a problem I had when I upgraded to Windows 10. I've done a clean install, but fast user switching has never worked. I am always logged out when I switch so all my running apps are terminated. Every time I try to switch, the above message appears in the event log (I think this may be the only time I see the message).

So I'm wondering whether I get logged off because the service failed.

Does anyone have any more information about why the service fails?

Sorry if this is slightly off topic.

No one of those solutions work for me. Error still in event viewer

A combination of deleting the OneSync Service (I'd already uninstalled One Sync) and setting the named services' "Start" DWORD value to 3 in HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services (see screenshot) worked for me.

I'm using win10 Pro and these services are only listed as being valid for the Home version so god knows why they are present in Pro.

WastedJoker said:

I'm using win10 Pro and these services are only listed as being valid for the Home version so god knows why they are present in Pro.

They seem to be required for the Mail, Calendar and People apps (maybe others) to function, for both login and sync. Those apps are present in all Windows 10 editions, as far as I know.

Was having a hell of a time with 100% disk activity and 90% CPU because of this ******* but... After removing it I did lose mail and calendar functionality as noted a few posts back. Unfortunately I removed it before then.

My question is, how to I restore/reinstall the service? I've verified APhostservice.dll is where it's supposed to be. I've downloaded an ISO and attempted a dism repair... No luck. The error message listed a few posts back isn't quite right. It's 0x80070424, and it's associated with trustedinstaller/windows update.

If I'm an idiot and missing something easy, feel free to call me out, but I honestly can't figure how to get the service installed an running short of a refresh, which seems like a really bad idea.

Appreciate any assistance you can render.

Seems no one wanted to take a swing at this... I figured a way around it for anyone who did delete the onesyncsvc as discussed earlier in this thread. I simply exported the registry folder from one of my machines that was still running a stock setup, ran the .reg file on my laptop and rebooted.

I did encounter another error when attempting to readd the account to mail. Received 'account already exists' but I was able to get into account settings via calendar and delete the account remnant in question. Rebooted and done. I've installed and verified the account as a means to verify the above procedure was valid.

I've attached the .reg folder from a clean pc. You can use it, or not, it's off a fresh install.

hi
may i know why is not OneSync Service listened in the service list services.msc ?

i can't find it even in process hacker , or process explorer
i can find it only with w10 task manager

by the way i have the same errors

The User Data Access_Session1 service terminated unexpectedly. It has done this 1 time(s). The following corrective action will be taken in 10000 milliseconds: Restart the service.

The User Data Storage_Session1 service terminated unexpectedly. It has done this 1 time(s). The following corrective action will be taken in 10000 milliseconds: Restart the service.

The Contact Data_Session1 service terminated unexpectedly. It has done this 1 time(s). The following corrective action will be taken in 10000 milliseconds: Restart the service.

The Sync Host_Session1 service terminated unexpectedly. It has done this 1 time(s). The following corrective action will be taken in 10000 milliseconds: Restart the service.

I marked it solved as the error was fixed for me and never got it again.