Can't download Adobe's page on Acrobate XI page correctly even when using latest Acrobate Pro

Well here's the "page" I am trying to download:  https://helpx.adobe.com/acrobat/11/user-guide.html# it is HTML.  I am using Acrobat Pro  2020 with a Lifetime License.

I am just downloading it because I already have Acrobat XI and have long since lost all the origianl documentation and  just wanted the User Guide.  I am using the latest Windws 10 Professional.

It really doesn't... Your description is pretty vague.

What is "Adobe's page on Acrobat XI" and why are you trying to download it using Acrobat, exactly?

Are you using Acrobat XI or "the latest Acrobat Pro"? What's your OS version? etc.