This happens to accounts that are configured in the iOS Mail app. The loading of unregistered MAPI services has been disabled by default to make Outlook more secure. 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. The person who sent you the invitation will need to remove your permissions and then send a new invitation. 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.

Currently, you can't use Outlook on Windows to edit calendars that are shared with your Outlook.com account, even if you've reconnected your Outlook.com account to Outlook. We're working to make it possible to edit shared calendars in Outlook 2016 for Windows. 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. You can use step-by-step Outlook troubleshooting Microsoft Support and Recovery Assistant to diagnose both Calendar and Mail issues that affect Outlook. To download and install the Assistant, see About Microsoft Support and Recovery Assistant. In some cases, an Outlook messaging profile may be misconfigured.

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 you close outlook(make sure its not in the system tray) then click on start and type Domain, then find Access work or school. You should see the Microsoft account, click on step-by-step Outlook troubleshooting it and disconnect it. I'm having an issue with one Outlook 365, the program open and get stuck at loading the user profile, any profiles. I decided to try and fix it by uninstalling and reinstalling. I also removed some old add-ins and an old, inactive account (but Outlook worked no problem with these for a long time).

For example, the first time you try to Dismiss All on a list of reminders, Outlook asks you if you're sure you want to do that. If you don't choose an option on that dialog box, Outlook won't let you do anything else. Pressing Alt+Tab will help you switch from window to window and help you see what dialog boxes might be stopping Outlook from responding.

Most of these crashes come down to one thing – problematic data files. PSTs and OSTs act like Outlook’s memory banks. When they get too large, go corrupt, or are poorly configured, step-by-step Outlook troubleshooting things start to break. This should resolve the issue of ‘Outlook keeps crashing’.

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

Read on to find out how to fix common Outlook problems below. This library of articles provides guidance to troubleshoot and fix errors that you may experience when using Classic Outlook for Windows. For a complete list of articles, browse the navigation pane on the left, or use the search box above the pane to filter by keywords and find help with a specific issue. If you're trying to set up an iCloud account, follow the steps in Add or manage an iCloud email account in Outlook. Then, each item in your calendar folder is checked for known problems that can cause unexpected behavior, such as meetings that seem step-by-step Outlook troubleshooting to be missing.

There are several possible reasons why Outlook behaves this way. Outlook Error 0x a shows an error of server timeout with Outlook’s receive/ send functionality. This error is caused due to connectivity problems and inappropriate settings with the files of Outlook data. Some configurational changes or default features of antivirus can restrict the connectivity of your Outlook to the server. You can either manually disable such features from your antivirus program or temporarily uninstall the antivirus from your machine.

Use the Microsoft 365 shared computer activation (SCA) troubleshooter to enable shared computer activation for Microsoft 365 applications. Use the uninstall troubleshooter to uninstall Microsoft 365, Office 2021, Office 2019, or Office 2016 from your Windows PC. If you have Outlook in your startup folder, remove the shortcut from the startup folder. Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. TrustedTech delivers unbeatable customer service, with experts in licensing and high-level technicians always on-call to answer your tech issues in-depth. Our Account Managers and Distribution Team fulfills orders quickly and efficiently, giving our customers digital downloads in record time so they can move on to their next big project.