This is given when the XDG_CACHE_HOME directory could not be used to create the 'media-art' subdirectory used for caching media art. This is usually an initiation error.
Storage information is unknown, we have no knowledge about removable media.
Title is required, but was not provided, or was empty.
File could not be renamed.
A call to symlink() failed resulting in the incorrect storage of media art.
Enumeration values used in errors returned by the #MediaArtError API.