I can’t deconstruct a level 3 specialized MPX. I am now level 8 and don’t need it. I believe it was an Ubisoft Club reward. I also can’t desconstruct the Exotics that I received for preordering (though I now see I can upgrade those to my current level and don’t want to deconstruct them anymore). When I try to sell the MPX at a vendor, it doesn’t even show up.