Just started with obnam. While backing up files via sftp works fine, when I'm trying to backup local files I'm getting only errors similar to the one in the post title.
There's not nearly enough information there to investigate the problem. Please see the http://liw.fi/obnam/bug-reporting/ page and then send the relevant information to the Obnam mailing list (see http://liw.fi/obnam/contact/ for details). Thanks.