[Mommigiggi]

go to settings and then system info, it should say somewhere what kodi version you are on. Mine says Kodi 16.1-RC2.

No, not true.
version 1.6.1 is the latest version for Kodi 15.
version 3.0.0 is in the offical repo already for Kodi 16.

DO NOT install any version after 1.6.1 on Kodi 15, it just won't fit.
and, DO NOT install the zip from github directly from Kodi - it will install the addon in "-master" folder, which will cause you to duplicate addons, and multiple instances and dozen of bugs. I mentioned it in this thread before.

Thank you for your replies. Does this mean that I have version 15 of Kodi? How do I check which version I have?

IIRC, Settings -> System Info -> you'll see in the bottom of the skin the full version name.. KODI 15.2 or something like this...
please download the latest version from kodi.tv. Kodi 15 (Isengard) is belong to the past
if you don't sure, backup your system first.

You are so helpful!! Ok, I'll go look for which version I have. Then I'll try to find out how to backup. When I said I was a newbie I was not kidding