Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
Yep, I had to install Lion on a VM to finally re-get the Mac App Store installer for El Capitan. Since Apple updated the 10.11 installer, why on earth they didn't remove this limitation?
Nuts!
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.