After installing the September Public Update, Outlook 2007 displays mixed languages in the user interface. You can start Outlook in safe mode, disable your add-ins, and then try to open Outlook normally. If you can't open Outlook, or Outlook disappears or crashes, one of your add-ins may be to blame or you may need to update Outlook. If you are having problems with Outlook, there are a few things we can help with to get you back to sending and receiving your email.

Outlook known issues in the October 2019 updates

If you manually type in the secondary connected account email address in the "From" field, the email is sent as "On behalf of" your primary Outlook.com account. When you start Windows normally, several applications and services start automatically and then run in the background. A Selective Startup or "clean boot" process can help you identify problems that are caused by application conflicts. The issues documented in this section have been reported after installing the recent credential loop in Microsoft 365 updates listed below. We're investigating the issues and will update this page when a fix is available. In the meantime, please use the workarounds suggested for each issue.

Outlook Known issues in December 2024 updates

This happens to accounts that are configured in the iOS Mail app. Until you can install the Windows Update fix release, you can set a registry key that will cause Outlook to stop using the local Windows Search service. When this registry key is set, Outlook will use its own built-in search engine. The built-in search will display the message below to indicate it is not using the Windows Search service. To access the calendar shared with your Microsoft 365 for business account, you'll need to accept the invitation from Outlook on the web, iOS, or Android. If you've already clicked the Accept button in Outlook 2016, you won't be able to re-accept the invitation from another Outlook application.

Outlook Known issues in April 2023 updates

If the check box is cleared, the service or startup program doesn't run when you restart the computer. You can also add the secondary connected accounts (Gmail, Yahoo, etc.) in Outlook.com as additional accounts in the Outlook inbox repair tool alternative profile. You might need to set Windows Update to automatically download and install recommended updates. Installing any important, recommended, and optional updates can often correct problems by replacing out-of-date files and fixing vulnerabilities.

VBScript does not run or you receive malicious code warning when using a custom form for Outlook

The folder may have been deleted or the server where the folder is stored may be unavailable. You don't have appropriate permission to perform this operation. Note that you can quickly tell how your mail is currently sorted, by the presence of a small triangle on the field headers.

• This issue affects all Outlook versions on Windows 7, Windows 8, Windows 10.
• You may have to contact your antivirus software vendor to determine how to configure the software to exclude any integration with Outlook or to exclude scanning in Outlook.
• You don't have appropriate permission to perform this operation.
• If you manually type in the secondary connected account email address in the "From" field, the email is sent as "On behalf of" your primary Outlook.com account.
• In System Configuration, if you select a check box, the related service or startup program runs when you restart the computer.
• If you typically use an Outlook.com account for email, this issue can occur if there are multiple aliases on the account and the 3rd party email address is the primary alias.
• For more information, see How to install the latest applicable updates for Microsoft Outlook (US English only).

Or, you can disable any antivirus software add-ins that are installed in Outlook. If you have email messages in an email program, you must import your email messages and addresses to the new user profile before you delete the old profile. If everything is working correctly, you can now delete the old profile. In System Configuration, if you select a check box, the related service or startup program runs when you restart the computer.





Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. If you use the cloud-based Microsoft Fix Outlook and Office 365 Errors 2025 365 on a PC or Mac, the automated Support and Recovery Assistant tool can diagnose and fix many issues, including Microsoft Outlook not starting. You may have to contact your antivirus software vendor to determine how to configure the software to exclude any integration with Outlook or to exclude scanning in Outlook. For a list of antivirus software vendors, see Consumer antivirus software providers for Windows. If the problem doesn't occur after you restart Outlook, one of the add-ins is likely the cause of the problem. Restore the add-ins one at a time until the problem does occur to determine which add-in is causing the problem.