Hello, I really need help.

[cashgrany]

Hello, I really need help, I was happy to switch to 3ds max 2020 but voila, my model appears like this? Why ?

[10DSpace]

@cashgrany 

Was this model imported from another application? If so, what application and how was it imported (via .fbx or .obj or 3rd party script) into Max? Also, if you post a screenshot of what it is supposed to look like, that might help.  

[cashgrany]

It's a plane, which I exported with 3ds max 2016 in .obj. I want to clarify that it does that only with the .obj?

[10DSpace]

@cashgrany 

Sorry, but how are we supposed to know what the plane is supposed to look like?  You show us the imported model in wireframe views and a shaded view which is black, possibly because of a material that is assigned that may not be compatible with the current renderer or due to surface normals being flipped.  But you haven't explained (or shown) at all what the problem is with the imported model vs the original max 2016 version.   Your title says you really need help.  Well, so do we in order to understand exactly what the problem is.   

[cashgrany]

Sorry for the lack of information. This is what the model looks like on 3ds max 2016.

[10DSpace]

@cashgrany 

Thanks. Now it is clear that the geometry doesn't even match in your imported max 2020 version.  It looks like from your max 2016 screen shot that the jet model may have been imported from a game engine with some type of plug-in that rips/imports models into max?   If so, is the plug-in used in some way in the modifier stack for the parts of the model in Max 2016?  This may or may not be relevant here depending on whether you converted all of the parts of the model to an editable mesh or editable poly in Max 2016 prior to exporting via .obj.   If you haven't already done this, then in a copy of your Max 2016 scene convert all parts of the model to an editable mesh or editable poly.  Then try to export the model to both .obj and .fbx formats and import into max 2020 to see if that corrects the issue.