Не мог обновить от 16,04 до 18,04, никакая реальная ошибка?

Я получил уведомление, что существует обновление для моей настольной установки, но я не могу сделать так. Нет никаких реальных сообщений об ошибках, что я вижу. Я работал sudo apt autoremove, sudo apt upgrade, и sudo apt install, и это дает 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. Это - мой экран, когда я работаю do-release-upgrade:

Reading cache

Checking package manager
Reading package lists... Done
Building dependency tree
Reading state information... Done
Hit http://us.archive.ubuntu.com/ubuntu xenial InRelease
Hit http://archive.canonical.com xenial InRelease
Hit http://security.ubuntu.com/ubuntu xenial-security InRelease
Fetched 0 B in 0s (0 B/s)
Reading package lists... Done
Building dependency tree
Reading state information... Done

Restoring original system state

Aborting
Reading package lists... Done
Building dependency tree
Reading state information... Done
=== Command detached from window (Mon Aug 20 20:34:56 2018) ===

Это - мой main.log:

2018-08-20 20:34:50,649 INFO Using config files '['./DistUpgrade.cfg.xenial']'
2018-08-20 20:34:50,649 INFO uname information: 'Linux egwene 4.4.0-133-generic #159-Ubuntu SMP Fri Aug 10 07:26:31 UTC 2018 i686'
2018-08-20 20:34:50,862 INFO apt version: '1.2.15ubuntu0.2'
2018-08-20 20:34:50,862 INFO python version: '3.5.2 (default, Nov 23 2017, 16:37:01)
[GCC 5.4.0 20160609]'
2018-08-20 20:34:50,864 INFO release-upgrader version '18.04.24' started
2018-08-20 20:34:50,868 INFO locale: 'en_US' 'UTF-8'
2018-08-20 20:34:51,059 DEBUG Using 'DistUpgradeViewText' view
2018-08-20 20:34:51,111 DEBUG enable dpkg --force-overwrite
2018-08-20 20:34:51,150 DEBUG creating statefile: '/var/log/dist-upgrade/apt-clone_system_state.tar.gz'
2018-08-20 20:34:54,329 DEBUG lsb-release: 'xenial'
2018-08-20 20:34:54,330 DEBUG _pythonSymlinkCheck run
2018-08-20 20:34:54,331 DEBUG openCache()
2018-08-20 20:34:54,332 DEBUG No such plugin directory: ./plugins
2018-08-20 20:34:54,332 DEBUG plugins for condition 'PreCacheOpen' are '[]'
2018-08-20 20:34:54,332 DEBUG plugins for condition 'bionicPreCacheOpen' are '[]'
2018-08-20 20:34:54,332 DEBUG plugins for condition 'from_xenialPreCacheOpen' are '[]'
2018-08-20 20:34:54,333 DEBUG quirks: running PreCacheOpen
2018-08-20 20:34:54,333 DEBUG running Quirks.PreCacheOpen
2018-08-20 20:34:54,721 DEBUG /openCache(), new cache size 56038
2018-08-20 20:34:54,721 DEBUG need_server_mode(): run in 'desktop' mode, (because of pkg 'ubuntu-desktop')
2018-08-20 20:34:54,721 DEBUG checkViewDepends()
2018-08-20 20:34:54,721 DEBUG running doUpdate() (showErrors=False)
2018-08-20 20:34:55,529 DEBUG openCache()
2018-08-20 20:34:55,939 DEBUG /openCache(), new cache size 56038
2018-08-20 20:34:55,940 DEBUG doPostInitialUpdate
2018-08-20 20:34:55,940 DEBUG plugins for condition 'PostInitialUpdate' are '[]'
2018-08-20 20:34:55,940 DEBUG plugins for condition 'bionicPostInitialUpdate' are '[]'
2018-08-20 20:34:55,940 DEBUG plugins for condition 'from_xenialPostInitialUpdate' are '[]'
2018-08-20 20:34:55,940 DEBUG quirks: running bionicPostInitialUpdate
2018-08-20 20:34:55,940 DEBUG running Quirks.bionicPostInitialUpdate
2018-08-20 20:34:55,951 DEBUG abort called
2018-08-20 20:34:55,951 DEBUG openCache()
2018-08-20 20:34:55,951 DEBUG failed to SystemUnLock() (E:Not locked)
2018-08-20 20:34:56,356 DEBUG /openCache(), new cache size 56038

Какова могла быть проблема здесь?

Править

Используя ссылку, предоставленную WinEunuuchs2Unix, вот мои ссылки PPA:

'http://us.archive.ubuntu.com/ubuntu/ xenial main restricted'
'http://us.archive.ubuntu.com/ubuntu/ xenial universe'
'http://us.archive.ubuntu.com/ubuntu/ xenial multiverse'
'http://security.ubuntu.com/ubuntu xenial-security main restricted'
'http://security.ubuntu.com/ubuntu xenial-security universe'
'http://security.ubuntu.com/ubuntu xenial-security multiverse'
'http://archive.canonical.com/ xenial partner'