The loading of unregistered MAPI services has been disabled by default to make Outlook more secure. To edit a shared calendar, go online to your own Outlook.com calendar, open Calendar for Windows 10, or use a mobile device. Maybe you've added a new program to your computer that doesn't get along with Outlook, or your system has a virus. Regardless of the specific cause, there are several key troubleshooting fixes to try that might help. If your antivirus software isn't up-to-date, Outlook may not function correctly. Outlook stores certain data, such as email signatures and the spelling checker dictionary, in the AppData folder.

Outlook known issues in the October 2019 updates

If so, wait a short time (usually two or three minutes) to see if Outlook starts working again. If you can't choose any of the menu options, type inside an email message, calendar event, or contact, Outlook may have frozen. There are three steps you can take to try to get Outlook working again. For more information, see How to install the latest applicable updates for Microsoft Outlook (US English only). There repair PST file without data loss is a new version of outlook that is web based, but still works like an app, and has less problems.

Outlook Known issues in December 2024 updates

The person who sent you the invitation will need to remove your permissions and then send a new invitation. Occasionally, classic Outlook tries to run a process in the background. Auto-archive, sending and receiving a very large attachment, or running some of the other mailbox tools can all be done in the background. Check the status bar at the bottom of the screen to see if another process is running.

Outlook Known issues in April 2023 updates

You may notice that All, Unread , Mentioned and other sort and filtering options, such as By date, and Newest are missing in Outlook above your email list. MAPI does not validate that a provider's DLL that it is requested to load is registered correctly in MapiSVC.inf or even that it comes from the local machine. This can be exploited by creating a file together with an OLE object in such a way to cause MAPI to load a DLL from a network share when the OLE object is activated. If you're using Outlook 2010, Outlook 2013 or Outlook 2016, uninstall and re-install reset cached Exchange mode iCloud to resolve this issue. This issue affects all Outlook versions on Windows 7, Windows 8, Windows 10.

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

If the network is performing slowly, Outlook must wait for read and write operations to the AppData directory to finish. To manage your mailbox by reducing the size of the Outlook data file, see Reduce the size of Outlook Data Files (.pst and .ost). Although add-ins can enhance your user experience, they can occasionally interfere or conflict with Outlook.

• This can be exploited by creating a file together with an OLE object in such a way to cause MAPI to load a DLL from a network share when the OLE object is activated.
• If the check box is cleared, the service or startup program doesn't run when you restart the computer.
• After updating Office, you may experience a brief flashing window every hour, which triggers the OfficeBackgroundHandlerRegistration task to start running.
• Outlook 2016 freezes when you try to preview an Excel file that's attached to an email.
• To edit a shared calendar, go online to your own Outlook.com calendar, open Calendar for Windows 10, or use a mobile device.

Here are some common fixes that should work when Outlook doesn't open, whether you're using Windows or a Mac. To manage your mailbox by using the AutoArchive feature, see AutoArchive settings explained. We recommend that you move several items in your larger folders to separate folders, or that you archive those items by using the AutoArchive feature. These steps are provided in a specific order based on commonality and complexity. Find solutions to common problems or get help from a support agent.





User profiles help make sure that your personal preferences are used when you log on to Windows. As your mailbox size increases, more resources are required to open each folder. If you have a large number of items in any single folder, you may experience performance issues Outlook profile repair and recovery steps during certain operations.