Malwarebytes has been up-dated and there is a new look to its pages. Also what was listed as 'Quick Scan' has now become 'Threat Scan'.
I think you were getting back the Free version which does have a few 'red crosses' to draw your attention to the Premium edition. The message about a Scan Not having been run on your computer was in effect telling you that a Scan had Not been done with the up-dated version.
Have another shot at downloading the Free version from the Official Site and let us know how things turn out. :-
http://www.malwarebytes.org/
Hans.