error 1001

Hi Jonathan, 

Please check this ongoing topic in Microsoft support: Outlook 365 app error 1001 on RDS environment ( FSLogix) - Microsoft Community
Skip to the last pages there are some fixes that work for some situations.

One of the fixes described there I've seen to resolve the 1001 error:

Hi everyone!

I've been following this thread for a while and so far, our client's environment has been stable since end of November. Here are the things to note so far:


Deploy these registry keys:
[HKLM\SOFTWARE\Policies\Microsoft\Windows\WorkplaceJoin]

"BlockAADWorkplaceJoin"=dword:00000001




[HKLM\SOFTWARE\Policies\Microsoft\Windows\WorkplaceJoin]

"autoWorkplaceJoin"=dword:00000000"




Delete these registry keys, if possible, Microsoft doesn't recommend using these anymore:
Computer\HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Common\Identity

EnableADAL

DisableAADWAM

DisableADALatopWAMOverride




If you're using FSLogix, make sure to enable this policy through main GPO:
RoamIdentity




Lastly, if users did register the RDS to Azure AD, might have to follow these steps:
- Download (WPJCleanup.zip) https://download.microsoft.com/download/8/e/f/8ef13ae0-6aa8-48a2-8697-5b1711134730/WPJCleanUp.zip

- Extract and run the .cmd file

- Confirm if the WorkPlaceJoined indicates "NO"

- Reenter credentials to outlook (might have to log out and log back in to the RDS)




Let me know if that helps or not. We're looking to deploy this to other clients since it appears to be working fine but I hope it helps with your case.

Hey thanks for the details. I will try it out and report back if I see any improvecment. 
I should check entra ID and conifrm no one is showing as registered for the RDS servers right? Is that what you mean by 

Lastly, if users did register the RDS to Azure AD, might have to follow these steps

So upon further invistagting the AVD hosts show a bunch of users as Entra Registered. I am wondering if I should delete all those entries after I create the registry entried to block workplace join. 

Jonathan Giraldo yes you can clean those up, did you manage to fix the 1001 error this way ? 

So the problem with this error is that it is happening at random times and random users. It could go for about 1 week or even a month with out happening. 
I implemented the tix and now I am on the lookout. 

I will keep you posted. 
Thank yoiu Jan!

Hopefully, this information helps, Jonathan Giraldo In addition to the steps discussed earlier, sometimes issues can arise from incorrect SSO settings, particularly when there’s an ADsync setup involved. Make sure to double-check the SSO settings in Azure AD Connect and verify the GPO for site-to-zone assignments that affect SSO. For more details: Setting up Single Sign On (SSO) with Azure AD Connect — LazyAdmin

I've been seeing this too sporadically on Win 11 hosts. Are you still needing to implement RoamIdentity, and disallow Workplace join via reg key?

Andrew Matt. So far I know this is still a thing when you encounter the error unfortunately

Yes it is still a thing and very intermittent, however I must state. The solution that Jan Scholte provided did help stabilize items alot!

Thank you

Thanks.

Interesting that RoamIdentity is helping; all the FSLogix and MS documents are saying it should be off except for maybe legacy items. They make it sound like its never really recommended! This issue seems to involve FSLogix two perennial issues; Appx handling and credential roaming (or not), so I might need to have to see what MS support can find. 

I've also seen MS giving some recommendations not to roam a few locations, but nothing from FSlogix on whether they already exclude these or not (scenario 2 below): 

Error “Something Went Wrong [1001]” signing in to Microsoft 365 Desktop Applications - Microsoft Support