When I try to upload an image on…

When I try to upload an image on https://ru.wordpress.org/, I get this error:

Unable to create directory /home/rosettaRosetta The code name of the theme for the local WordPress sites (eg. bg.wordpress.org is a “Rosetta” site). All locale specific WordPress sites are referred to as “Rosetta sites.” The name was inspired from the ancient Rosetta Stone, which contained more or less the same text in three different languages./public_html/wp-content/blogs.dir/15/files/2011/04. Is its parent directory writable by the server?

Is uploading not allowed?