Third-party add-ins are helpful… until they’re not. Outdated or conflicting ones can mess with Outlook’s core performance, causing unexpected slowdowns or outright failure to launch. Create your account and connect with a world of communities.
Some programs running on the back of your computer may conflict with Outlook and cause Outlook to crash. To see if that’s the problem for you, restart your computer, and then reopen Outlook to see if it runs correctly. Test if Outlook is functioning correctly after disabling Microsoft Outlook troubleshooting help the add-ins. If not, it means still Outlook keeps crashing. Let us try another solution to get this issue fixed soon. If Outlook does not crash, this indicates that one or more Add-ins are to blame for the Outlook 365 crash.
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 Microsoft Outlook troubleshooting help frozen.
Learn how to check the version of Outlook you are using and update your Outlook. This is intended as a general guide to some common errors and I may not be able to troubleshoot through this. Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support.
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 Installing any important, recommended, and optional updates can often correct problems by replacing out-of-date files and fixing vulnerabilities.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.
Not something you want to take on lightly, but sometimes you have to. Similar to our earlier suggestion of repairing Office (see #3 Repair Your Microsoft Office above), perform the same steps except choose to Uninstall. Be aware that you may need your product key if you received one.
The root cause was the deployment of an incorrect campaign data file, which led to false positive campaign detection. We have since reverted to the right data file and the outbound email flow has returned to a normal state. We also released a new rule that corrected the wrong campaign verdict for all impacted customers during the incident. If you're having problems sending or receiving email, read how to Fix Outlook.com email sync issues. Maybe you've added a new program to your computer that doesn't get along with Outlook, or your system has a virus.
Use the classic Outlook calendar check troubleshooter to identify classic Outlook calendar issues. Use the classic Outlook profile setup troubleshooter to set up Microsoft 365 email in classic Outlook. TrustedTech delivers unbeatable customer service, with experts in licensing and high-level technicians always on-call to answer your tech issues in-depth. TrustedTech is dedicated to being a reliable resource for all software and technology support needs.
ProcedureExit Outlook.Open a Run dialog box. ...Type Outlook /safe, and then click OK.If the issue is fixed, click Options on the File menu, and then click Add-Ins.Select COM Add-ins, and then click Go.Click to clear all the check boxes in the list, and then click OK.Restart Outlook.Jun 25, 2025
Then, each item in your calendar folder is checked for known problems that can cause unexpected behavior, such as meetings that seem to be missing. After you've selected a task, you can use the details pane to do things like add more information, add steps, or mark as important. You can view more than one calendar at a time, add other calendars, choose which calendar to display, and create new calendars. You can use the Inbox Repair tool (SCANPST.EXE) to diagnose and repair errors in your Outlook data file. The Inbox Repair tool checks the Outlook data files on your computer to see if they're in good shape. Use the People page to find, view, create, and edit contacts and contact lists.
To learn more about managing contacts in Outlook.com, go to Create, view, and edit contacts and contact lists in Outlook.com. Each message also has a mini toolbar when you open the message in a new window. For each message, you can delete it, mark it as unread, flag the message, or pin it to keep it at the top of your folder. Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. We have multiple tools to help you automatically diagnose an issue, troubleshoot, and fix problems with Outlook.