Does Catalina No Longer Support Bootable MacOS X Partitions on Flash Drives when Formatting as Mac Journaled?
I am having great difficulty trying to install a MacOS X that actually works on my mid 2011 27" iMac. I bought it at a great price, and it is immaculate as it just sat in a corner of a business unused. I am well aware it is old (and unsupported), but it is very upgradable and was affordable.
We also have 2 MacBook Pros. My son took the (2019?) i9 off to college with him because he cracked the right screen edge on this one (which we, the parents, have to deal with, now). You would think a "Pro" version of anything wasn't such a snowflake. I just updated to MacOS X Catalina on this 2015 model i7 (and it was updated last night). But everything is different.
I am not used to MacOS X being so drastically paranoid, either.
I am trying to create a Flash Drive to install MacOS X El Capitan on the 2011 27" iMac using this 2015 MacBook Pro, but all the tutorials online are so drastically different than this OS. It seems that I cannot format a USB Flash drive the same way (MacOS X Journaled File System with GUID) as I see in all the online tutorials I find.
The thing is, this El Capitan version of MacOS X is the last version of MacOS X that the 2011 iMac will support in its stock configuration. I hope to upgrade it to a 'Metal' supported graphics card that will work with that system eventually, but right now I downloaded MacOS X El Capitan to the iMac and it erased the MacintoshHD. That was fine with me, it was a new system for me and I wanted a clean install of a good, stable OS where I could securely browse the internet (which which the stock Lion MacOS X does not allow for because only browser that works on it is Chrome which is unsupported in that OS).
But, this post is not about the iMac, I am simply trying convey the issues related to trying to create a Bootable USB Flash Drive for it. Still it is important to note because the original El Capitan MacOS X distribution installer that I downloaded isn't available as removable media from Apple. And after failing to install from the download, I tried to install El Capitan through the internet, but I always get a "required download missing" message. So, I have no option but to create the Bootable USB Flash Drive Installer for El Capitan.
Curiously, lots of software no longer works on Catalina. But I have to use it to create that USB install drive, if I can. Yet, the Disk Utility interface is so different from all the tutorials online I am wondering if this will even work. I have no partitions option for the inserted USB 3.0 Flash Drive inserted into this 2015 MacBook Pro USB port. Erasing the drive and formatting it as MacOS X Journaled doesn't make any new options magically appear, either.
Did I just screw myself up by upgrading to MacOS X Catalina on this mid 2015 i7 MacBook Pro? Or is there some option I am missing so that I can ensure that I am formatting the Flash Drive as MacOS Extended Journaled with GUID support?
I am trying to return to MacOS after Windows 10 Pro keeps forgetting my settings and absolutely killing my productivity, but I am extremely alarmed because I can't get MacOS X installed on the iMac (and there is no help here?) and now it seems that I may have messed-up upgrading to Catalina since nothing works and everything is different and I can or cannot create a Bootable Flash Drive to install El Capitan on the older iMac?
MacBook Pro 15", macOS 10.15