I tried "Reset Layout" in the Mechanical window. The blank content area moved from the right side of the window to the left for a couple seconds, then moved back, but otherwise everything is the same.
I tried opening a new project and then a new Mechanical Model. That works fine, but there is still nothing in the content window. I think there should be a ruler and an x/y/z arrowhead, but those aren't there. I'm an IT guy, so I don't know what to do with it beyond that.
Do you have a known-good sample project with a Mechanical model that I could download and try?
You are navigating away from the AIS Discovery experience