Problem solved. I downloaded installed the new Addon Manager. I don't remember having to do that before. Any, time to fly... 
You had to do it now, because the new Addon Manager requires the VC++ 2013 runtimes, which are now included in all our installers but, if you installed KLAX with an installer you already had, the VC++ 2013 weren't included so, if you never installed them in your system, no software using them would work, that's why you had to download the Stand-Alone Addon Manager, so that is installed the VC++ 2013 for you.