Lamopart

I think this error because ,the account may have exceeded its storage limit or have an issue with its mailbox settings,and you can just manually migrate the emails from the Office 365 account to the Google account using an email client such as Outlook or Thunderbird. This would require downloading the emails from the Office 365 account and then uploading them to the Google account, but may be necessary if other migration methods are not working. Or try using a different migration tool to transfer the user's email from Office 365 to Google. There are several third-party migration tools available that may work better for this particular account , give Sharegate or Gs Richcopy 360 a try , I think all can help alot

It may be worth checking to ensure that you have the latest version of Microsoft Office 365 or Microsoft 365 installed on your computer. You can also try contacting Microsoft support for assistance with accessing the feature.