If Outlook fails to start even in Safe Mode, it means that there is a problem with the Outlook profile or with the Outlook installation.
Here are some troubleshooting steps that you can try to fix Outlook failing in Safe Mode:
Create a new Outlook profile. This will create a new set of Outlook settings and folders. To create a new Outlook profile, go to File > Account Settings > Account Settings, and then click on the Add button. Select Manually configure server settings or additional server types and then select Internet E-mail. Enter your email address and password and then click on Next. Select IMAP as the Account Type and then enter the server settings for your email provider. Click on Next and then Finish.
Repair Outlook. This will scan your Outlook installation for errors and try to fix them. To repair Outlook, go to File > Account Settings > Account Settings, and then select the account that is not working. Click Change, and then select Repair.
Reinstall Outlook. If repairing Outlook does not fix the problem, you can try reinstalling Outlook. To reinstall Outlook, go to Control Panel > Programs and Features, and then select Microsoft Office. Click Change, and then select Repair. If the repair option is not available, you can select Uninstall and then reinstall Outlook.
Update your antivirus software. Outdated antivirus software can sometimes conflict with Outlook and cause it to fail in Safe Mode. Make sure that your antivirus software is up to date.
Update your operating system. Outdated operating systems can sometimes conflict with Outlook and cause it to fail in Safe Mode. Make sure that your operating system is up to date.
If your Microsoft Outlook is not receiving emails, then this blog will solve all your problems, also explaining why and you can again enjoy your outlook mail. This blog also covers issues to fix Outlook failed in safe mode. How do I fix Outlook failed in safe mode? It happens when the user has problems with add-ins. Follow the following steps to disable all your add-ins before restarting Outlook. Open start menu and search "appwiz. cpl" and open the program. Now, select Microsoft office 365 pro plus and select change. Make sure you choose the option showing online repair and then run repair. Later, open Outlook. It may ask for safe mode again> Select NO. These steps help you with how do I fix Outlook failed in safe mode issue.