How to fix 0xc0000005 error on MS Outlook causing Oulook crash globally

In the incident notice, the Microsoft 365 Admin Center confirmed the error and suggested that users use the web or mobile version instead until the problem is resolved. According to some other users, rolling back to an old version of Outlook will help fix this problem.

If you get error 0xc00000005, here are two workarounds you can do:

Method 1: Roll back to the old version of Outlook, released 6/2020

To return to the version of Microsoft Outlook released on June 24, 2020 to troubleshoot the problem, follow these steps:

B1: Open a command window by clicking Start Menu and typing CMD . When the command window opens, click it.

B2: In the command prompt , type cd "Program FilesCommon Filesmicrosoft sharedClickToRun" and press Enter .

B3: Currently, you have been moved to the ClickToRun folder. Type officec2rclient.exe / update user updatetoversion = 16.0.12827.20470 and press Enter .

B4. The downloader will be activated to download the special version of Microsoft Office and roll back to the old version. You need a bit of patience because this process will take a few minutes, depending on your computer configuration and network speed.

B5. When the update is completed, the "Updates were installed" message will be displayed and you just need to click the Close button .

B6. Now that Outlook has been rolled back to the old version, you can start Outlook to start work.

Some users will not find this method effective. Then, you need to replace the command at B3 with officec2rclient.exe / update user updatetoversion = 16.0.12527.20880 to solve the problem.

Method 2: Run Outlook in Safe Mode

If you do not want to roll back to an earlier version of Microsoft Office, you can run Microsoft Outlook in Safe Mode. However, you should note that in Safe Mode, all Outlook add-ons, including security utilities, will be disabled.

To start Outlook in Safe Mode, follow these steps:

B1: Press and hold Ctrl button on keyboard then run Microsoft Outlook. Outlook will start and ask if you are sure you want to run it in Safe Mode.

B2: Click Yes to confirm.

B3. After booting, you will see the Safe Mode indicator displayed in the title bar.

You need to repeat these operations every time you want to start Outlook in Safe Mode.

Good luck!