From your screenshot, when you clicked through to the installer debug page at the end, it seems that the log was reporting problems with the wrong site registration key (both for Toolset and WPML).
Have you moved this site recently?
In any case, I suggest you click the "registered" link to go to the custom OTGS installer page and un-register the site, then follow the links to re-register the site which will create new site keys if necessary. (Do this for Toolset, and also for WPML if you have it installed.)