Yosemite 10.10.5 upgrade to El Capitan?

Question

macOS

I actually downloaded the El Capitan update from the AppStore. I

run the installer, we get to the disk selection and try to select our working disk.
We get the message:

Maybe I'm doing something wrong and I need to update it differently?

Answer 1

You apparently have an MBR partition and you installed the version from _Archi from under Windows.
If so, then you have one way out, put on a blank disk.

Answer 2

Check the markup scheme as written in the Parameters.