Amazon S3 backup failing with escape error

I see another very similar thread posted a few days ago, but it doesn’t look like the same issue so I am posting in a new thread.
A scheduled backup which has run successfully 15 times has just failed with the error:

Can't escape \x{0301}, try uri_escape_utf8() instead at line 120

I have googled the error but haven’t found anything to help. Can anyone point me the direction of the cause?

Just bouncing this to the top as I still have backups failing with this error. Can anyone help?

Could anyone even tell me the path to the file mentioned in the error message, so I can take a look and see what I can work out?