S3 file upload - Access Denied

I can connect to a S3 bucket and can download files but when I try to upload a file I get an "Access Denied" error.
Is there a way to set the encryption level. I suspect that is the issue but any other suggestions are welcome.

Can you upload the file using any other S3 client?

WinSCP does not support encryption levels.

Yes I can upload with another S3 client. It uses SSE-S3(AES-256) which I understood to be the same as the default encryption level for WinSCP and S3 if I read the documentation correctly.

Please post verbose log files from both WinSCP and the other client.

I have the same problem. I can not manually load file to s3 bucket in WinSCP but can in S3.

@jackcarroll3: What exactly does it mean "can in S3"? Can you upload the file using aws s3 commandline?