You will get this generic error in Live writer. It’s based on a permission problem when trying to post to Subtext.
If you are hosting Subtext on your own public server, or ISP..in either situation, the Subtext skins/yourskin/images folder must have write permissions for Network Service account on your domain server, or else you will get this error when trying to post with a picture in Live Writer to Subtext 2.1
