Is there no more supported version for Ubuntu 16.04? That’s what I get if I try install:
W: The repository ‘http://download.opensuse.org/repositories/isv:/ownCloud:/desktop/Ubuntu_16.04 Release’ does not have a Release file.
N: Data from such a repository can’t be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: Failed to fetch http://download.opensuse.org/repositories/isv:/ownCloud:/desktop/Ubuntu_16.04/Packages 404 Not Found [IP: 2001:67c:2178:8::13 80]