[Question] I been having problems converting a OBJ to m2

[arthas242]

I been having problems converting a OBJ to a M2, i use MES to convert it into a OBJ and works fine in 3d max 9, my problem is once i am done with the changes i try converting it back to a m2 and it say error to many vert/faces or wrong model*then somehting about cake XD*, i tried converting a model inject some one else did to a obj that worked then back and same thing, does MES OBJ to M2 even work becuase if i do a model already changed it doens't even work?

if it doesn't, can u explain to me how i can do it or u could do it for me since i posted it in obj

heres the obj
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