Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. In this window you can check the status, the number of failed requests (under Req/Fail), and which mailbox is experiencing the issue. Outlook email accounts are provided to employees, students, alumni, retirees, and for generic accounts.

If Outlook is configured to connect to the Exchange mailbox in Online mode, an .ost file is not used. To adjust the number of days of data that are synced for shared folders, add the following registry values. You can limit the synchronization window that’s used for calendar folders to reduce the number of items that are stored locally in your calendar folders.

For more information about working with calendars in Outlook.com, go to Using the calendar in Outlook.com. Select More to see additional actions—for example, an option to print a message. If you want to learn about printing, see Print attachments received in email messages. 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 Installing any important, recommended, and optional updates can often correct problems by replacing out-of-date files and fixing vulnerabilities. To install the latest Windows and Office updates, click the link below.

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. 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 steps to fix Outlook not opening frozen.

Last but not least, you can try to repair Outlook PST files using the ScanPST tool or using a specialized Outlook repair tool. If your Outlook data file is damaged, you’ll need this tool. It’s built into Outlook and helps repair PST and OST files. Also, you can recover permanently deleted items and attachments from Outlook with the help steps to fix Outlook not opening of this Outlook repair tool.

If this does not resolve the Outlook 365 crash issue, proceed to the next solution. Priyanka Kumari is a technical content writer in the fields of Email Migration, Data Recovery, Cloud Migration, and File Management. She is dedicated to simplifying complex technology terminologies for all users. Her articles and guides demonstrate her commitment to streamlining email management for professionals or businesses of any size.

Warning This workaround may make a computer or a network more vulnerable to attack by malicious users or by malicious software such as viruses. We do not recommend this workaround but are providing this information so that you can implement this workaround at your own discretion. Use this workaround at your own risk.If your antivirus steps to fix Outlook not opening software includes integration with Outlook, you may experience performance issues in Outlook. In this case, you can disable all Outlook integration within the antivirus software. Or, you can disable any antivirus software add-ins that are installed in Outlook.

Sometimes you’ll open Outlook and then for no apparent reason, it will freeze or shut itself down. There are quite a few different causes for this, but one of the most common is a defective add-in. Here’s how to disable add-ins in Outlook even when it keeps crashing. 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. Find solutions to common problems or get help from a support agent.

After updating Office, you may experience a brief flashing window every hour, which triggers the OfficeBackgroundHandlerRegistration task to start running. In this case, sign in to the Microsoft 365 portal by using your administrator credentials, and then select service health to determine whether other customers are experiencing the same issue. If other customers are experiencing the issue, the issue should end when the service-interrupting event is resolved. If you’d like to share any feedback about this article, please let us know.

Our relationship to the Microsoft Partner Network allows us to provide competitive pricing and authentic software and support, all with a much-needed human element. A lot of times, a user will click on something by accident and change their view and be unsure of how to get it back. Sometimes when a user tries to search in Outlook, it either returns incomplete results, or returns steps to fix Outlook not opening nothing at all, even if you can see the email normally. Most times, this is caused by a corrupted search index, which you can rebuild. Keep in mind this does take a while, and it’s usually best done after the user has left for the day.