I noticed Loupe for the first time with my update to 4.1.5. I undocked the Loupe window and cannot get the Loupe to dock again. Previously, it was docked in the bottom portiion of the screen entitled “Application View Message Explorer Loupe” next to Message Explorer. I like the idea of a floating window, which helps to resize larger and put it on a different monitor. Just can no longer get it to dock where it was originally.
I just found the answer to this by accident. I was having the same issue. I held down the ALT and SHIFT keys and drug the Loupe window around and was able to dock it.