S3 Backup fails

I have MyCloud DL4100 and I try to use the built in S3 Backup for one of the folders in my NAS.
I creates user with all possible S3 permissions, a bucket and all my tries to backup just keeps failing.

I know this thread:

I keep getting this 103 error code (S3StatusErrorNoSuchVersion) that I don’t know hoe to deal with.

What to I do wrong? Someone can help please?