create installer for any os before High Sierra (Including) on Catalina

So "The instructions do work if you are running macOS Catalina."

After downloading the linked ElCapitan download at step....

I get the following.

So in my experience I get a dialogue box with a clear statement that the OSX 10.11 can not be installed on a MacBook Pro with...

I don't know what else to add to get help on this issue. I do thank you for trying to help.

Sure. Great. and I know. However the fact remains that the following is not true in the pure sense of the context.

If those instructions I followed included "borrow a High Sierra Computer.... etc" that would have helped, but the problem as I described it was that I needed to get a ElCapitan installer using Catalina. I know that if I could get an installer onto the Catalina I would be fine but I couldn't and THAT was the point.

So I stand by the following screen shot.

As I have not been able to create in installer ON (MY) Catalina FOR a MacBook that NEEDS ElCapitan OS, using Apple support instructions explicitly. The instructions do NOT work, at least on my MacBook Pro. and that is the point.

I appreciate the explanation of this paradox as to why. But my friends why it does not work, does not get the job done. An explanation of how to get the job done would. So the Apple support is incomplete or there is some other problem with my Catalina system that prevents the "installer" from being Installed so that I can use terminal to extract it to an external drive. Which I say again I used with success on a High Sierra machine after it would NOT work on a Catalina machine. So I know how to use it right. By default it is implied that unsupported hardware creates a requirement to use terminal to create a bootable installer, but you can't do that if you can't unpack the installer from the .dmg file to create the installer, can you?

Anyways thanks for the support. I appreciate it.

Thanks but this is contrary to your first response telling me how to create an installer for ElCapitan on Catalina. Which does not work. Despite Catalina not creating an installer I was able to borrow a computer with High Sierra to create the installer for ElCapitan and ultimately fix my older MacBook Pro, by installing a native os (ElCapitan) on it.

Thanks for trying to help.

Thanks again for your help. However the dialogue boxes refer to "installing" the ElCaptain package so according to Apple terminology, the process for creating an installer requires installing the package. This may seem moot, however I do believe that my terminology is consistent with apple terminology. I know that you may not have been aware that I was NOT attempting to install ElCaptain OS on either the 2016 MacBook Pro or the early 2011 MacBook Pro which I ultimately did use to create the installer for the mid 2009 MacBook Pro I need working. However if you read my subject line, "create installer for any os before High Sierra (Including) on Catalina" it should be obvious that I was trying to create an installer image.

I don't want to sound ungrateful. Sometimes text based communication is difficult to interpret, and I know most support requests are poorly and even badly stated. So I can never fault anyone for not understanding clear and concise communications in mast cases. In my case however I feel as my communication was clear. In hind site I can see after all that my problem is actually "why can't I create an installer for ElCapitan on Catalina, which I still can not do, as you can see by the screen shots.

At this time I will consider case closed as I now have my 17 inch 09 MacBook Pro booting again as I was able to create an installer on a High Sierra machine.

My lesson is After installing Boot Camp, don't get fancy and try to install Ubuntu as a third boot partition just for fun, because it isn't and it doesn't.

I wish you a great day.

Case closed.

Thanks again.

I would like to add that it appears to me that you work for apple, if you don't would not have written this reply as it is not my place to steer private individuals in any direction. If you are a private individual I will retract all of my reply and thank you agin for your help.