MS Office 365 is a cloud-based suite offering tools like Word, Excel, and Outlook, known for its compatibility and security. However, it requires regular backups and updates to avoid errors that could impact your important mailbox data. You can Troubleshoot by Restaring your system and checking Internet connectivity, updating your System and updating Office 365, Disabling Add-Ins, or stopping ClickToRunSvc service.

There are more ways to Repair Office 365 on Windows. But, there is the best approach to fix this by using a SysInfo Office 365 Backup Tool to repair Office 365 on Windows. https://www.sysinfotools.com/office365-backup.php