Are you using the latest version of our software? If not, can you post the version you are using. Reviewing previous posts, there was another user who posted something similar and the MSP360 team suggested that it may be related to a known Google issue with files that have a "%" character in their name. So, you may want to do a quick check of files and see if one exists with a "%" and, if so, rename if possible.

I find the easiest way to do this is to use a Command Windows and search like:
dir *%* /s / q /b > PctResult.txt

Then you can review the PctResults.txt text file for all the matches.

The team also mentioned that using the service account or OAuth authentication instead of access/secret seemed to be a workaround for now.

You can also turn on detailed logging and review the logs after the failure (make sure to turn logs off or set to low when analysis is complete).

But, if this does not work, please feel free to submit logs via the Tools | Diagnostic toolbar option for the team to review and reference this post when submitting.

Thanks.

Thanks David for your suggestion. the version, I am using is 6.2.6.3 . I was able to backup successfully with service account. I am now looking forward to the next cycle, just to confirm, everything is working well.

There's a known problem when using old creds. Service account authentication should work fine. The issue is related to some minor changes on Google's side and it will be fixed soon.