In perusing Reddit I discovered that someone associated with the Kodi forums may have tried to censor this information.  So, I figured I’d give them a little taste of the Streisand effect.  And this is useful technical information that should be made available, IMHO, because new versions of software sometimes introduce bugs not present in older versions.  This was originally posted by Kodi forum user opensorce in a thread that no longer exists. USE THIS INFORMATION STRICTLY AT YOUR OWN RISK!  I SUGGEST DOING A FULL SYSTEM BACKUP BEFORE YOU PROCEED.

If you’re running Ubuntu 14.04 and you’re having trouble with Kodi 15 Isengard you can return back to 14.2 by doing the following:

1) Follow the instructions here to completely remove Kodi from your system

2) Download these two files: https://launchpad.net/~team-xbmc/+archive/ubuntu/ppa/+files/kodi-bin_14.2~git20150327.1058-final-0trusty_i386.deb and
https://launchpad.net/~team-xbmc/+archive/ubuntu/ppa/+files/kodi_14.2~git20150327.1058-final-0trusty_all.deb for 32 bit and https://launchpad.net/~team-xbmc/+archive/ubuntu/ppa/+files/kodi-bin_14.2~git20150327.1058-final-0trusty_amd64.deb and https://launchpad.net/~team-xbmc/+archive/ubuntu/ppa/+files/kodi_14.2~git20150327.1058-final-0trusty_all.deb for 64 bit.

3) Install Kodi-bin then Kodi for a return to 14.2 (“dpkg -i kodi-bin*” and then “dpkg -i kodi_*” without the quotes should do it)

4) Be sure not to allow any updates to Kodi until you want to change to 15.

Note: Some users have experienced issues with dependencies after uninstalling 15. Be sure you follow all the instructions to uninstall 15 before re-installing 14.2.

Hope this helps!

EDIT: Although my own efforts with this method have proven successful on Ubuntu 10.04 and 12.04 wsnipex says “this will probably break on anything but ubuntu 14.04”. So be aware!

Later comments in the thread indicated that additional dependencies may be required (so watch the output of the dpkg commands when you run them and look for missing dependencies, which can usually be installed using apt-get) and/or that “sudo apt-get -f install” may need to be run in order to fix missing dependencies.  Also there were comments to the effect that this will ONLY work with Ubuntu 14.04 and not with any other version of Ubuntu.  I suspect that’s because the downloaded files are from the “trusty” section of the repository, and that if you were running a different version you’d need to obtain the proper .deb files for that version.

EDIT FOR THOSE WISHING TO DOWNGRADE TO KODI VERSION 15.2: If you are attempting to downgrade from Kodi 16 to Kodi 15.2 on a Ubuntu 14.04 64-bit system, these may be the files you will need: https://launchpad.net/~team-xbmc/+archive/ubuntu/ppa/+files/kodi-bin_15.2~git20151019.1039-final-0trusty_amd64.deb and https://launchpad.net/~team-xbmc/+archive/ubuntu/ppa/+files/kodi_15.2~git20151019.1039-final-0trusty_all.deb – I have downloaded and saved these files as a form of insurance, so that I can get Kodi Isengard back in the event that my HTPC crashes and burns, but I have not actually attempted an install using them. I did this only because the TVHeadEnd PVR addon in Kodi 16 is again broken (but in different ways than before) in Kodi Jarvis, and there is no firm indication of if or when the Kodi developers will fix these new issues, only that they don’t plan to fix them at all in Jarvis. If you install these, and have any problems that you need to resolve before they will run, I would appreciate it if you would leave a comment to that effect).

Here is another method from a post by user hd789 in a thread on the Kodi forum that may work with Ubuntu 15.10:

DOWNGRADE KODI 16.0 TO 15.2 IN UBUNTU 15.10 INCL TVHEADEND:

$ sudo add-apt-repository ppa:team-xbmc/kodi-old
$ sudo apt-get update
$ apt-cache showpkg kodi
$ sudo apt-get install kodi=2:15.2~git20151101.0902-final-0wily kodi-bin=2:15.2~git20151101.0902-final-0wily
$ sudo apt-get install kodi-pvr-tvheadend-hts=2.1.18-2~wily kodi-pvr-hts=2.1.18-2~wily
$ sudo apt-mark hold kodi kodi-bin kodi-pvr-tvheadend-hts kodi-pvr-hts

I would just call your attention to the fact that all these files are specific to a particular version of Ubuntu, in other words, the files that will work under Ubuntu 15.10 won’t work work under Ubuntu 14.04. Note that if you have Synaptic installed on your system, then after running the first two commands above (sudo add-apt-repository ppa:team-xbmc/kodi-old and sudo apt-get update) above you should be able to see the old kodi-related packages in Synaptic and install them from there. That is how we got Kodi 15.2 installed on a Ubuntu 14.04 system recently. It appears that repository contains versions for Ubuntu 14.04 (trusty) and Ubuntu 15.10 (wily).