This article describes how to troubleshoot the following kinds of issues in Microsoft Outlook when it’s used together with Office 365:
- Outlook stops responding (hangs).
- Outlook crashes even though you aren’t actively using it.
- Outlook crashes when you start it.
To help troubleshoot Outlook issues in an Office 365 environment, follow these steps.
Step 1: Investigate possible issues caused by add-ins
- Exit Outlook.
- Open a Run dialog box. To do this, use one of the following procedures, as appropriate to your version of Windows:
- If you’re running Windows 10, Windows 8.1, or Windows 8, press the Windows logo key+R.
- If you’re running Windows 7, click Start, type Run in the Search box, and then click Run.
- 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. If the issue doesn’t occur, start adding the add-ins one at a time until the issue occurs.
Step 2: Repair Office
- Open Control Panel, and then click Uninstall a program.
- In the list of installed programs, right-click the entry for your Office installation, and then click Change, and then click Online Repair.
Step 3: Run Outlook Diagnostics
- Run the Outlook won’t start automated diagnostics to fix the issues.
Click Run when you’re prompted by your browser.
- If the tool doesn’t resolve the issue, go to Windows or Look to start Microsoft Support and Recovery Assistant for Office 365 (SaRA).
- On the first screen, select Outlook, and then select Next.
- Select any of the following options, as appropriate, and then select Next:
- Outlook keeps hanging or freezing
- Outlook keeps crashing with a message “Microsoft Outlook has stopped working”.
SaRA runs some diagnostic checks, and returns possible solutions for you to use to try to fix Outlook connectivity issues.
Step 4: Create a new Outlook profile
If you ran SaRA in Step 3, and you created a new profile, you can skip all of Step 4.
- Open Control Panel, and then click Mail.
- Click Show Profiles.
- Select the profile that you want to remove, and then click Remove.
Removing the profile also removes associated data files. If you’re not sure whether the data files are backed up or stored on a server, do not remove the profile. Instead, go to step 4.
- Click Add.
- In the Profile Name box, type a name for the new profile.
- Specify the user name, the primary SMTP address, and the password. Then, click Next.
- You may receive the following message:
Allow this website to configure alias@domain server settings? In this message, click to select the Don’t ask me about this website again check box, and then click Allow.
- When you’re prompted, enter your logon credentials, and then click OK.
- When Setup is finished, click Finish.
This step creates detailed information about your Outlook configuration and provides solutions for any known issues that are detected. It also gives you the option to upload your results to Microsoft so that a Support engineer can review them before you make a Support call.
- Click Outlook Advanced Diagnostics.
- Click Run when you are prompted by your browser.
Reference Article: Outlook crash or stop responding when used with Office 365 – Exchange | Microsoft Docs