My mesh becomes messed up when I join different mesh. Why is this happening?

Please someone help me with this. I am a beginner, started working on a model few weeks ago but i was using blender 2.8, when i came to know about an update, i quickly upgraded to 2.82a but my blend file got all weird after re importing. But when I separated the mesh in edit mode, by materials or by lose parts,mesh becomes normal again. I have linked the images as well as the blender file regarding the problem. I have tried importing and exporting using fbx, obj etc. I also removed all of the shape keys but it also did not fix the problem. The file still opens and works fine in blender 2.8 though. this issue is also happening with 2.81. Please I really need help with this THANKS! This is after separating or before joining

This is after joining mesh(using ctrl J)

Blend file https://drive.google.com/open?id=1KNnAh_Hxqvh1U13GGNjy6QK5Zc_utLq_

Sorry, I just tried it and it imports just fine in Blender 2.82.7

When I open a blend file from previous versions I will open the Gear ico in the upper Right of the open dialogue, and uncheck LOAD UI, you never know what from the earlier version UI might mess up. It usually doesn’t, but you never know.

Note: One thing I noticed, you have not applied Scale and or Rotation ( Ctrl+A ) . Apply Scale
Just for reference, if you don’t many, many things will just flat mess up, and you will not know why. Try to apply Scale after you move, join scale or just edit something on the mesh, it doesn’t hurt and can save a lot of headaches!

Thanks for the quick reply!
I’ll make sure to apply transform, I usually forget doing that.
But I am still facing the same problem, so I’ve switched back to 2.8, could it be something specific for my pc? Because most of the new external models I try to import have same problem, they do fine if I don’t join the mesh, but the moment I press Ctrl+J, everything gets messed up. But then again, these models are not messed up as they load well in blender 2.8 and 79 so maybe my pc doesn’t support the new versions. Is that possible?

I suppose that could be it, But I wouldn’t think so. I recently upgraded my GPU, but before I had a really old GPU and CPU is about 5 years old, and it would run all the versions up to 2,83. It may just be your drivers. Let me ask, how do you update Blender, From the installer, or from the .zip? I always use the .zip and just dump the contents to a Blender folder, and make sure to add in a Prefs Folder in the internal 2.8 folder ( for startup as it makes each version independent of the others).

If you use the installer, it can get corrupted from previous versions.

I tried both. zip and installer after when the zip didn’t work. And yeah, my pc is also very old. It couldn’t run the alpha of blender 2.80 but when stable version was released, it was able to run it. Same goes for 2.83 alpha which I tried today.

Well that may-be the answer then…If I can ask, what are your system specs?

Yeah, that is an old one…Is that a Laptop? Still, it doesn’t explain why 2.8 will run and 2.82 doesn’t…there is not that much difference between them. Or why it jumbles the mesh…
Was the original file created in 2.80? then imported to 2.82a…
If so…try opening in 2.8 and apply scale and rotation, save, and try again…Might just work…

Here is mine…

Specs

Damm your pc is amazing. Mine is not a laptop, blender 2.82 doesn’t even open on my laptop, 2.8 does open but is slow.
However my pc runs blender 2.8 quite efficiently.

No, applying transform will not work. As literally no model is opening in my blender 2.82. I tried downloading some online models in all sorts of formats as well. Everything works fine in 2.8 but it doesn’t make any sense to me why is this happening. And the problem is only when all the mesh is all joined. I cannot with a lot of separate meshes as then i wont be able to use shape keys.
here look at this https://imgur.com/TDP0ncg

I tried opening your file in 2.81 2.82 and 2.83 and it was completely fine in all three.

Thanks for checking out! As I said above, The models are all fine, so it doesn’t make sense why It is not opening in my PC and opening in 2.80 :sob: