Error code received using My Passport for Mac

I have previously backed up to this drive with no problem, but today I received the following error message:

"time machine couldn’t complete the backup to my passport for mac because the backup disk was previously encrypted but is no longer encrypted”

How can I fix this?


You could refer to the following link:

Thanks. I’ll check it out.

Hi. I followed the link you sent me, but I don’t understand how it addresses my problem. Thanks.