E: Type '' is not known on line 1 in source list /etc/apt/sources.list
E: Type '' is not known on line 1 in source list /etc/apt/sources.list
E: The list of sources could not be read.
E: Type '' is not known on line 1 in source list /etc/apt/sources.list
E: The list of sources could not be read.
E: Type '' is not known on line 1 in source list /etc/apt/sources.list
E: Couldn't read list of package sources