Я получаю следующие сообщения об ошибках:
N: Ignoring file 'openboard-xenial.list.save.1' in directory '/etc/apt/sources.list.d/' as it has an invalid filename extension
E: Type 'sudo' is not known on line 2 in source list /etc/apt/sources.list.d/openboard-xenial.list
E: The list of sources could not be read.