I go through the insert/part procedure. It appears in yellow and moves with my curser. When I place it on my screen with a click, the part disappears...but the planes (and sketches) are visible. Weird thing is nothing shows up in the model tree. Weirder yet, as I continue with the command, I can place these planes to the original model but still no visible body and nothing new appears in the model tree. It might be a clue that I can insert a different part with no problems.