Forum Discussion
Cannot launch Outlook 365 offline - "the set of folders cannot be opened"
Windows 10 21H2 (OS Build 19044.1706)
Office 365 2204 (Build 15128.20178)
I'm unable to launch Outlook 365 offline. I get the error: "Cannot start Microsoft Outlook. Cannot open the Outlook window. The set of folders cannot be opened. The attempt to log on to Microsoft Exchange has failed." Once Outlook has started and successfully connected, I can then go offline, but if I am not online during launch I can never get in.
I've tried:
- starting in safe mode
- sfc /scannow
- dism /online /cleanup-image /checkhealth
- creating a new profile
- creating a new C:\Users\...\appdata\local\Microsoft\Outlook folder
- toggling cached exchange mode on and off
- toggling "turn on shared calendar improvements"
- disabling "download shared folders" in advanced account settings
- disabling "favorites" in the folder pane
- creating a registry REG_DWORD key HKCU\Software\Microsoft\Office\16.0\Outlook\AutoDiscover\ExcludeScpLookup with Value 1
None of these change the behavior.
Any ideas?
- Found a fix! Set created key in HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\AutoDiscover
DWORD ExcludeExplicitO365Endpoint = 1
Now I can start offline. As a bonus, Outlook also launches much faster.
6 Replies
- Bonus Tips - always have a backup of email data on cloud or external storage media.
I would suggest you to try Email backup solution - third party backup tools can be used but first try the demo prior to go with premium, check the strength and effectiveness and authenticity. - Found a fix! Set created key in HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\AutoDiscover
DWORD ExcludeExplicitO365Endpoint = 1
Now I can start offline. As a bonus, Outlook also launches much faster.- Please how did you do this?
- Instructions at https://medium.com/jj365/outlook-issue-with-direct-connect-to-office365-352dd29de65
- Thanks. This works for my users. I was not able to figure it out. Notice it affects more older version of outlook. Current ones don't have such Autodiscover issues.
