What does "maximum event re-entrancy depth exceeded" mean?

I am making a game about smashing stuff. When a thing is smashed, all the parts go anchored = false and move around. After 4 seconds the parts reassemble. The game crashes when the parts reassemble and the output says "maximum event re-entrancy depth exceeded" like 20 times at once. What does that mean?

Background: 5 parts of the total 17 part model have the reassembling script. Here's the script.

function changed()
    if script.Parent.Value ~= script.Parent.Parent.Position then -- The script.Parent is a vector3value and records the original position of the part.
    script.Parent.Parent.CFrame = CFrame.new(script.Parent.Value) --The script.Parent.Parent is the part.
    end
    end

script.Parent.Parent.Changed:connect(changed)