after the last Microsoft 365 Update, Outlook isn't working.

Question

After the last Microsoft 365 Update, Outlook isn't working. I've tried repairing the program, checked the settings and it still doesn't work. I share this Microsoft account with my wife and her email is working. Any ideas on how to repair this?

Answer 1

Hi, I'm John!

To narrow this down, are you using New Outlook for Windows, Classic Outlook for Windows, or Outlook for Mac?

What exactly happens when you open Outlook? Does it crash, freeze, or show an error message?

Answer 2

Try the following steps in order, testing Outlook after each step:

1. Install the latest Windows and Office updates
   • Outlook often fails after an update if not fully up to date.
   • Run Windows Update to install all pending updates.
   • Then install Office updates as described in Install Office updates.
2. Repair the Outlook profile
   • Open Outlook (classic Outlook for Windows).
   • Select File > Account Settings > Account Settings.
   • On the Email tab, select the problematic account and choose Repair.
   • Follow the wizard and then restart Outlook.
3. Repair Office
   • Close all Office apps.
   • Open Control Panel > Programs and Features.
   • Find the Microsoft 365/Office installation, right‑click it, and choose Change.
   • Select Online Repair (or Repair) and complete the process.
4. Repair Outlook data files
   • Close Outlook.
   • Run the Inbox Repair Tool (SCANSPST.EXE) as described in Repair Outlook Data Files (.pst and .ost) to scan and repair the data file for the affected account.
5. If the account still will not connect, create a new Outlook profile
   • Close Outlook.
   • Open Control Panel > Mail > Show Profiles.
   • Select Add, give the profile a name, and follow the Add Account wizard to add the email account.
   • In Mail, select Always use this profile and choose the new profile.
6. If connection issues persist only for this mailbox
   • Run Windows Update again and confirm Outlook is fully updated.
   • If using classic Outlook for Windows with a Microsoft 365 mailbox, run the Outlook connectivity troubleshooter (Run Tests: Outlook User Connectivity) from the Microsoft 365 admin side if available.

These steps address the most common causes after an update: outdated components, a damaged profile, or corrupted data files, and they explain why one user on the same PC can work while another cannot.

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References:

• Fix your Outlook email connection by repairing your profile
• Fix Outlook connection problems for Microsoft 365 account
• Outlook not responding, stuck at "Processing," stopped working, or freezes
• Classic Outlook not responding, stuck at "Processing," stopped working, or freezes
• Outlook crashes or stops responding when used with Office 365
• Outlook won’t open or is stuck at loading profile