On one of my multisites I get the following error message when trying to upload any media: "Unable to create directory http://www.domain.com/wp-content/blogs.dir/18/files/2013/08. Is its parent directory writable by the server?"
Firstly, the directory already exists as I see it when SSHing into the site. Secondly, I even recursively set the entire blogs.dir folders to 777. But I still get this error.
This is the only site of 14 on my multisite install that gives me this error.