Solved / Need urgent advice how to handle .iso files

I need to install Halion on my new Mac laptop. I have got the download links to two .iso files from Steinberg support.

I’ve managed to download one of the files to my old desktop computer, then using an external hd to transfer it to my laptop, where it’s now waiting for me to get hold of file #2.

After downloading file #2, this time on the laptop, Safari is saying “cannot write file”. Simply put, why?

How should I handle .iso files after download? Can I simply double click to install?

I got the help I needed from Steinberg support. They have been marvellous every time I’ve asked for help.