New Outlook will not open

Question

New Outlook will not open. This has been going on for two days now. I keep getting the following:

I am forced to use Classic Outlook which is not as good or reliable.

Answer 1

Hi, I'm John! I will help you with this.

That particular error (Microsoft.Exchange.Data.Directory.ADDriverStoreAccess NonLocal Exception) usually points to a temporary issue with the connection to Microsoft’s servers.

Just to confirm, are you using Outlook with a work or school account, or is it a personal Microsoft account (like Outlook.com or Hotmail)?

If you haven't tried anything yet please start by:

Restart your PC:

• This helps refresh any background Outlook or connection issues.

Reset the new Outlook app:

• Press the Windows key and search for Outlook.
• Right-click on it and select "App Settings".
• Scroll down to the Terminate section and click "Terminate".
• Then scroll down to the Reset section and click "Reset".
• Wait a moment, then try opening the app again to see if it works.
• If the issue persists, go back to the same settings, scroll down to the Reset section, and click on "Reset" (confirm the action if prompted).
• Restart your PC and test.

Check for Windows updates:

• Sometimes system updates include fixes for Outlook connectivity issues.
• Go to Settings > Windows Update, then click Check for updates.

Try Outlook on the web:

• You can also sign in at https://outlook.com to make sure your account itself is working fine.

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Let me know how it goes or if you have any further questions or concerns.

Click "Add comment" to let me know.

Regards,

John J.D.

Answer 2

The error shown is a service-side Exchange/MAPI failure when launching new Outlook. There is no client-side fix in the provided material, but there are two supported remediation paths and one workaround path that can be applied immediately.

1. Use the official new Outlook reset
   • Close new Outlook.
   • Run the reset command for new Outlook so it clears its local state and forces a fresh connection to the service the next time it starts:
     • From the referenced guidance: run olk.exe --clearLocalState.
   • Start new Outlook again and re‑enter the account credentials when prompted.
   • This recreates the local profile/cache for new Outlook and has resolved similar “something went wrong” startup failures.
2. Clear new Outlook and auth local data
   • Close all Microsoft apps (Outlook, Teams, etc.).
   • Open the AppData folder (Windows + R → appdata).
   • Delete the following folders so they are recreated cleanly:
     • C:\Users\<UserName>\AppData\Local\Microsoft\Olk
     • C:\Users\<UserName>\AppData\Local\Microsoft\OneAuth
   • Restart Windows.
   • Launch new Outlook and sign in again.
3. Use classic Outlook or Outlook on the web as a workaround
   • Until new Outlook can connect successfully, use classic Outlook for Windows or Outlook Web Access (OWA) to send and receive mail. These are the documented workarounds when Exchange connectivity issues prevent classic/new Outlook from opening normally.

If, after resetting local state and clearing the Olk/OneAuth folders, new Outlook still fails with the same Exchange error, the issue is likely on the service side. In that case, continue using classic Outlook or OWA and contact the mail service administrator or Microsoft 365 support so Exchange Online support can investigate and mitigate the backend error.

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References:

• New Outlook has stopped working, Fails when starting after 2026-01 Security Update (KB5074109) (26200.7623) - Microsoft Q&A
• Detected a problem launching new Outlook - Microsoft Q&A
• Error when opening classic Outlook: "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."
• Troubleshoot Outlook for Windows issues