yosemite guest

I'm running Parallels 16 on MacOS Catalina with a Yosemite guest OS to use iWeb. When I open iWeb the windows do not render correctly. At first look they appear blank but some of the page content appears to be placed outside of the window borders. How can I get the pages to render correctly?

Hi to all, I have to make OS Yosemite running if possible in Parallels on a Mac with Catalina installed. Can you help me please? Is it possible? If it not work in Parallels, does you know a possibility how I could fix it? Thank you all in advance, Horst