18.04 downgrade from bionic-proposed to main
87680
How to reverse '-proposed' channel package upgrade?
16526
Should I upgrade to the "mainline" kernels?
129
How do I find out which version and derivative of Ubuntu is right for my hardware in terms of minimal system requirements?
99687
update-alternatives --install says it needs link name path priority?
74953
Wake-on-LAN quit working with latest kernel (Bionic)
109539
How can I perform an offline upgrade using Ubiquity on the installation disc?
89166
How to downgrade Kernel
16050
Can I upgrade Xubuntu 18.04 32-bit?
144172
How to upgrade to a point release from the same base release (12.04 to 12.04.03)
83960
How do I change my update server in Ubuntu 18.04?
94446
Revert to upstart
3612
Can I downgrade to Mavericks after installing Yosemite (beta/developer preview)?
100700
How to remove the Unity Amazon package in 16.04?
136555
Bionic: Block Notification: laptop Battery Critically Low
132739
Will Ubuntu 18.04 LTS still support Upstart or do we have to change to systemd?
24165
Upgrade to version newer than repositories
42634
How do I upgrade to the development release (aka. Ubuntu+1)?