Chosen Solution
I created a bootable USB with Mac OS X El Capitan using terminal. I erased the HDD with disk utility and when I go to boot up the mac from the USB it shows the Apple logo and loads to a circle with a slash in it. I can get to the recovery but it wants to install Mac OS X lion. What is causing this circle with a slash and how do I in stall the OS X El Capitan that is on my USB?
This is not an answer but confirmation. I have two external SSD flash drives from old Apple SSD machines in OWC Envoy drive enclosures. One with 10.11 and one with 10.12. Both of these drives were bootable when I set them up. I used them for repairs and system and program installations. Now neither are bootable, I too get the circle with the line through it. I think Apple has done an update that somehow leaves them inoperable. Maybe @danj knows what is going on. https://eshop.macsales.com/item/OWC/MAU3…
