I installed Fred today and its dependencies.
I selected the Fred (Creative One Page Theme) for the 4 pages in my website. Except for the Home page, it removed the content in the content pane.
Step to reproduce
Click on “Open in Fred” button in the document editing pane.
When I click on “Open in Fred” it open the page in a new window, but there is no Fred UI, just the Home page content. I viewed source and can see that all the HTML is there from the Theme.
According to the video at https://fred.modx.com/ there’s supposed to be a Fred editing area at the bottom of the page.
MODX Cloud, version 2.71, latest build of Firefox. I’ve tried the same thing in Safari with the same result. Mac Mojave 10.14.4