Just for clarity, can you install apps other than Kodi?
If it's just Kodi that's the problem then I suggest completely uninstalling it and starting from scratch. I think the problems have come from an incomplete uninstall. These steps should completely remove all traces of XBMC/Kodi and allow a fresh install:
Go to Settings - More - Apps.
In the install app list:
Find XBMC (the pre-installed 13.1). Select 'force stop' if the button is available. Now select in turn 'Clear cache', 'Clear data' and 'Uninstall'.
Find Kodi. Select 'force stop' if the button is available. Now select in turn 'Clear cache', 'Clear data' and 'Uninstall'.
Find SPMC. Select 'force stop' if the button is available. Now select in turn 'Clear cache', 'Clear data' and 'Uninstall'.
That should have purged XBMC/Kodi/SPMC and associated data from your system.
Now reinstall Kodi (http://kodi.tv/download/) and/or SPMC (http://spmc.semperpax.com/). Note that SPMC needs to be the website version (not Play Store) for it to run on the Q5.
Hope that helps.