In case you get this error message when you upload an image:

“Failed to write file to disk”

Check this solution:

This message is related to WordPress files that connect to uploads.

Our recommendations are:

– Check that upload folder permissions are 777 or 755 – help http://codex.wordpress.org/Changing_File_Permissions

– Check with your hosting to see if your disk space is not full and you need to upgrade hosting