Backup failed

I just bought the 4TB My Passport for Mac and it was working fine then I get this error message?

Time Machine could not create a local snapshot to back up from. Latest successful backup: August 15, 2020, 9:47 PM. I was wondering if anyone could please help me out with this error?

Hi,

You could refer to the following link:

Thank you for the reply. it works now but only when I take my Macbook Pro off the charger. Is there any other way to use this with the Macbook Pro still being able to charge?