Last Updated: March 27, 2026 ISSUE Starting around March 12, 2026, classic Outlook might crash and then prompt to start in Safe Mode. This issue is happening when older builds of classic Outlook are using the newest version of the Teams Meeting Add-In build 1.26.02603. For example, this issue happens on Current Channel if the classic Outlook build is equal or lower than Version 2402 (Build ...

To install a standalone version of classic Outlook for Windows, select your language from the dropdown, and then select Download. Follow the prompts to complete the installation. Which language do you need? Tip: You can also try installing classic Outlook from the Microsoft Store.

For issues that are not covered on this page, we have multiple tools to help you automatically diagnose and fix a range of classic Outlook problems. Check out this article: Resolve Outlook for Windows issues with automated troubleshooting tools.

When you install Office, an Inbox Repair Tool (SCANSPST.EXE) is also installed on your PC. The Inbox Repair Tool can resolve issues by scanning your Outlook data files and repairing errors.

Classic Outlook for Windows stores all your email messages, meetings and events, contacts, and tasks in data files. These files occasionally might become corrupted.

Use the classic Outlook startup troubleshooter to diagnose and fix several common classic Outlook for Windows issues for you. Select the button below to start the classic Outlook startup troubleshooter. You need to be on Windows 10 or higher to run the troubleshooter.

Last Updated: July 10, 2025 ISSUE When you open or start a new email, classic Outlook crashes. This issue occurs because Outlook cannot open the Forms Library. This issue can occur for Outlook on all Microsoft 365 Office channels. The emerging cases for this issue are on virtual desktop infrastructure (VDI).

If you still have sync issues after installing the update, repair the POP Outlook Profile using the steps in the article, Fix your Outlook email connection by repairing your profile.

After updating to Version 2407 Build 17830.20138 or higher you find that Outlook may unexpectedly close at start up. Outlook will also close if you test in Safe Mode. This issue has been found to occur if the server-based rules for the M365 email account are corrupted or that Outlook cannot process. STATUS: WORKAROUND.

Type Outlook.exe /safe, and click OK. Tip: If Windows can't find Outlook.exe /safe, try using the full path to Outlook (for example C:\Program Files\Microsoft Office\OfficeXX, where XX is your version number).