Was bezig met Duinsoft verhaal en kreeg deze waarschuwing:
W:The repository 'http://extras.ubuntu.com/ubuntu xenial Release' does not have a Release file., W:Data from such a repository can't be authenticated and is therefore potentially dangerous to use., W:See apt-secure(8) manpage for repository creation and user configuration details., W:The repository 'http://www.duinsoft.nl/pkg xenial Release' does not have a Release file., W:Data from such a repository can't be authenticated and is therefore potentially dangerous to use., W:See apt-secure(8) manpage for repository creation and user configuration details., E:Failed to fetch http://extras.ubuntu.com/ubuntu/dists/xenial/main/binary-amd64/Packages 404 Not Found [IP: 91.189.92.152 80], E:Failed to fetch http://www.duinsoft.nl/pkg/dists/xenial/all/binary-amd64/Packages 404 Not Found [IP: 141.138.169.201 80], E:Some index files failed to download. They have been ignored, or old ones used instead.
Kan iemand mij vertellen wat er mis is??