How to Fix Outlook 365 keeps Crashing Issue?

Outlook 365 is a robust email messaging and calendaring application. However, you may face a situation where the email client freezes, stops responding, or crashes when opening it or sending the emails. This can disrupt your email communication and impact productivity since you won’t be able to access or send/receive new emails. The Outlook 365 keeps crashing issue can occur due to several software or hardware-related issues.

To fix this issue, you need to find out what's actually causing the Outlook to crash. In this article, we will mention the reasons that can lead to the Outlook 365 keeps crashing issue and shared some detailed solutions to quickly troubleshoot and fix this issue.

Reasons for Outlook 365 keeps Crashing Issue

There are multiple reasons that may trigger or cause Outlook 365 to crash. These include but not limited to:

• Corrupt Outlook profile
• Conflict with add-ins or security apps
• Outdated Outlook client
• Oversized or large OST file
• Insufficient system resources
• Network issues
• Graphics acceleration or drive issues

Solutions to Resolve Outlook 365 keeps Crashing Issue

Follow these solutions in the given order to troubleshoot and fix the Outlook 365 keeps crashing issue.

1. Run Outlook in Safe Mode and Disable Add-ins

Incompatible or faulty add-ins can lead to various issues in Outlook. To investigate and check if an add-in is causing the problem, run Outlook in Safe Mode. When in Safe Mode, Outlook runs with limited features and does not load any add-ins. The steps to open Outlook in safe mode and disable the add-ins are as follows:

• Close Outlook, if running.
• Press Windows + R, type Outlook.exe /safe, and press the Enter key.

• Choose your profile, if prompted. This will start Outlook in safe mode.
• Go to File > Options > Add-Ins.
• Click the Go button beside the Manage COM Add-Ins option.
• Uncheck all add-ins to disable them and click OK.

• Close Outlook and then start it normally.

• If Outlook doesn't crash, it means one or more add-ins are responsible for the issue. To find which add-in is causing the issue, enable each add-in and observe Outlook. If it crashes after enabling an add-in, uninstall that add-in.

2. Check for Outlook Updates

Your Outlook may be running on an outdated build or version that may be prone to bugs or issues. By updating Outlook, you can fix these bugs which may resolve the Outlook keeps crashing issue. The steps to update Outlook are as follows:

• Open Outlook (if it is opening).  
• Go to File > Office Account > Update Options.
• From the available options, choose Update Now.

• If a new update is available, Outlook will start a wizard and download the latest updates. Complete the update wizard.

3. Disable Hardware Acceleration

Hardware Acceleration (if enabled) may lead to freezing, crashing, or slow performance in Outlook. This happens if the graphics hardware on your system is either incapable of handling the Outlook demand or the driver installed is outdated. You can disable the Hardware Acceleration in Outlook to resolve the issue. The steps are as follows:

• In Outlook, go to File > Options > Advanced.
• Under the Display section, select Disable hardware graphics acceleration.

• Click OK.

4. Reinstall Graphics Driver

You may also encounter this issue if the graphics driver on your system is outdated or faulty. You can check and update the driver to resolve the issue. The steps are as follows:

• Press Windows + X and then click on Device Manager from the list.
• In the Device Manager window, find and expand the Display adapters section. You will see your graphic card listed there.

• Right-click on the graphics card and choose the Properties option.
• Then, navigate to the Driver tab to view details about the current driver, including the driver version and date.
• 

To update the graphics driver, follow these steps:

• In the Driver tab, click on Update Driver.
• Choose Search automatically for updated driver software.

Alternatively, you can also reinstall the graphics driver. All you need to do is:

• Right-click on your graphics card under Display adapters and choose Uninstall device.
• Confirm the move and make sure to check the option Delete the driver software for this device if available or Attempt to remove the driver from this device checkbox, and click Uninstall.

• Restart your computer after the driver is uninstalled.
• After the restart, Windows will automatically attempt to reinstall a basic version of the graphics driver automatically.
• To install the latest driver, download or run the driver setup downloaded from the manufacturer’s website and follow the on-screen instructions to complete the installation.

5. Check System Resources

Outlook requires more RAM (memory), processing power, and faster storage when OST file or mailbox grows large to process the information to/from the OST file. Make sure your system has enough or sufficient resources. If the system is old or running on minimum hardware, you need to change the hardware or upgrade the system.

6. Disable Conflicting Apps

Some software or apps, such as antivirus or antimalware, may conflict with Outlook 365, leading to crash. In this case, you can temporarily disable the antivirus or the security app. If this fixes the issue of Outlook 365 crashing, you must add Outlook 365 as an exception in the software.

7. Use Microsoft Support and Recovery Assistant

You can also use the Microsoft Support and Recovery Assistant for Office 365. It is a tool by Microsoft that helps identify and resolve issues with Microsoft products, such as MS Office, Outlook, etc. You can use this tool to troubleshoot and resolve the Outlook 365 crashing issue. The steps are as follows:

• Download and install the Microsoft Support and Recovery Assistant tool.
• After the installation, launch it.
• From the options, choose Outlook.

• Select Outlook stops responding or freezing option.

8. Repair MS Office

Sometimes, problems with the Outlook or MS Office program files can lead to such issues. In such a case, you can try repairing the MS Office installation or reinstalling the MS Office. The steps to repair MS Office are as follows:

• Back up your OST file. The file is usually located at:
  C:\Users\YourProfileName\AppData\Local\Microsoft\Outlook.
• Then, open Control Panel and click Uninstall a program.
• Select Microsoft Office and click Change.

• Select the repair option and follow the wizard to repair the MS Office.

• After the repair is complete, restart the system and then open Outlook. Observe Outlook and check if it crashes.

If Outlook is still crashing, try uninstalling MS Office completely from the system using the Office Uninstall Support tool and install it again.

Read more, How to backup your OST file data?

9. Create a New Outlook Profile

Outlook may keep crashing if the profile associated with your Office 365 (Microsoft 365) account is corrupt or damaged. You can create a new Outlook profile and remove the older one. However, before removing the profile, backup your current Outlook data file (OST) from the default location. The steps to create new Outlook profile are as follows:

• Open Control Panel and click Mail.
• Click Show Profiles.

• Click Add. Type the Profile Name and click OK.
• Set up the new profile with the same email account.
• After the setup, select the new profile in Always use this profile.

• Start Outlook and check if the Outlook 365 keeps crashing issue is resolved.

10. Increase Available Space in Mailbox

If the Outlook mailbox is full, it may lead Outlook 365 to crash as it can’t write or store new information in the Outlook data file. In such a case, you can try to increase the mailbox (OST file) size limit or increase the available space by removing old mail items and deleting trash or delete items. To manage the Outlook 365 storage space, you can archive older emails. Here are the steps:

• Open Outlook and go to the File tab.
• Select Info > Cleanup Tools > Archive.
• Check the Archive setting and select Archive this folder and all subfolders options.
• Choose the mailbox item you want to archive from your Outlook profile.

• Select a date in Archive items older than.
• Click Browse to choose a save location.
• Make sure to mark the “Do not AutoArchive” checkbox. Click OK.

11. Recreate Outlook Data File

If nothing worked and Outlook 365 is still crashing or freezing, try recreating the Outlook data file (.OST). The steps are as follows:

• Close Outlook.
• Press Windows+R, type %LocalAppData%/Microsoft/Outlook.
• Press the Enter key or click OK. This will open the default OST file location.
• Copy the xx@xx.com.ost file to an external media or different drive volume.
• After backup, right-click on the OST file and choose Delete.
• Start Outlook. This will automatically create a new OST file and sync all mail items from the mailbox server.

After the synchronization is finished, check all your mail folders. If you find missing mail items or mail folders, use an OST to PST converter software, such as Stellar Converter for OST, to extract missing items from the backup OST file and save them in PST file. After that, import the PST file into your new OST file via the Outlook Import/Export wizard. This will help you restore the missing mail items.

Conclusion

Outlook 365 keeps crashing is a common issue that users experience while accessing their email accounts in Outlook. There are several reasons that can trigger this issue. In this article, we've explained some methods to resolve the Outlook 365 keeps crashing issue. Sometimes, a partially damaged or inconsistent and large-sized OST file can also cause Outlook to crash or freeze. You can recreate the OST file after taking the backup to resolve this issue. To restore any missing mail items, use OST to PST converter software, like Stellar Converter for OST.