Sometimes for whatever reason the dependency does not install and needs to be installed manually.
Since it is used by so many Addons this can be a problem if it fails to install automatically.
Why it fails to install can be any number of reasons from hardware to software versions.
One quick work around is to download and install it manually.
The location the Zip file is stored after downloading will vary depending on the hardware used with it usually in a Download Folder.
Window PC users will need to create a Temp folder on C: and copy it from Downloads since Kodi can not see any Desktop Folders.
Steps To Install Kodi Six Dependency
1… Go to http://kodi-addons.club/addon/script.module.six/1.9.0 and download the newest Six version Zip file.
For PC users create a TEMP folder on C: since Kodi can not see any Desktop folders and copy the Six Zip file to it.