Windows 11, Desktop Client gets 0x800701AA

We’re migrating to Windows 11. On a machine installed with Win11 from scratch the Desktop Client hangs.
Settings: Virtual Files, syncing the directory structures is done within 60 seconds, downloading a single file less than 1MB sometimes works, in most cases after some MB the download stalls and ends in a 0x800701AA error.
It’s persistent from Desktop Client 3.6 up to 3.10.x
Error occurs even when Windows firewall and virus protection are disabled and no proxy is used.
No problem occurs with Win 10.
The moment you take the machne out of the company’s network and plug it into your home router everything works fine.
I guess ist’s some Windows policy new on Win 11 (or, likewise, working different than on Win 10), our Windows guys don’t have he faintest idea. Policies are set just the same as on Win 10.
Lucky enough the same error is reported for ther cloud syncing tools like DropBox, it happens even with the OneDrive client with only unstasfying workarounds as “solution”.

Does anyone have an idea?

I found two reports with this error code, is there something in common?

I suppose you have other Win11 machines where everything works.

So it should be possible to find the issues. Do you have logfiles that might give a hint what the client was doing just before the crash?

Just thinking, if you suspect a Windows policy, do they log stuff? But the policy applies as well when you are on the home network?

What I would try, if you don’t see the issue on other computers, try to connect a different account, just to avoid that there is something specific to the files of this account (there can be stupid stuff like leading spaces in filenames etc.).

The first one is mine.

The second one might have a similar reason.

I suppose you have other Win11 machines where everything works.

Yes and no. This error occurs reproducibly on Win 11 machines that are installed from scratch with all policies of our domain network that worked fine on Win 10.

Machines within our domain network and with the same set of policies that were migrated from Win10 to Win11 worked fine, until on Nov. 21 Wndows Updates KB5032190 and KB5032007 were installed (this is currently only a correlation and not yet a causality). On machines migrated from Win10 to Win11 the sync process now stalls without any error message on a lot of files take a long time for syncing (up to some hours). Syncing some GB might take a weekend.

There is nothing logged on Windows.

On test systems, we have ruled out the possibility that the original problem was related to the Windows firewall, our reverse proxy or our anti-virus software.

Some years ago we had a similar problem with timeouts while syncing that started after, again, our internal Patch Day. At that time we found out that some process under Windows was causing a TCP/IP timeout. There were vague indications that Windows Defender could be active and cause trouble, even when it was supposed to be deactivated. As a solution, we added the Nextcloud address to the trusted sites in the Windows configuration and everything worked again. However, the current problem is independent of this setting.

The same error is also documented for OneDrive, without the “solutions” being worth more than a few helpless “workarounds”.

Just thinking, if you suspect a Windows policy, do they log stuff? But the policy applies as well when you are on the home network?

Windows got three types of network: domain, private and public. There might be different policies for each, but since our machines should only be used in the domain network there are no differences in the policies (although it seems that policies ar working different on different network types…)

What I would try, if you don’t see the issue on other computers, try to connect a different account, just to avoid that there is something specific to the files of this account (there can be stupid stuff like leading spaces in filenames etc.).

Been there, done that. It’s a hard error.

So I wrote this entry in case there is somebody out there with an idea what could be causing this mess. As far as I unterstand it, It’s definitely caused by Windows not by Nextcloud.

I checked your other topics, seems you already tried all the easy stuff I could come up with. Sorry. Fingers crossed that someone steps in to help you out :crossed_fingers:

Thank you, I hope that someone reads this topic and remembers that there was another similar problem somewhere else that disappeared with some simple trick, like the thning with the “trusted sites” I mentioned.

It’s obviously a problem with windows and not with the sync client, but it makes he sync client useless in a lot of contexts.