Hey I have the same problem here . On my Laptop I can use Nanite and on my main machine I cant.
Both have the same graphics driver : 511.79 and the same windows version Windows 10 Pro 21H2 build 19044.1645
On both machines I have Direct x12 as the default RHI and the sm6 experimental ticked
The Laptop has a 3080 and the main machine a 3090 thats the main difference . I cant figure out why one is working and the other one isnt 
@ckutalec
You are my hero. I tried everything suggested here, and that worked.
I upgraded my graphics drivers, updated windows, nothing. I could make new projects with nanite, but older projects would not work with nanite.
All I had to do is input “r.Nanite.RequireDX12=0” and everything worked fine.
Anyone else have any other suggestions on how to sort this out? I’ve tried every suggestion in this thread and still no nanite visualisation for me
No idea what else to try other than wait for an engine update that might fix this
I am also having the same issue still I don’t know how to figure it out :-(.
Doesn’t help me, I have tried everything.
Installing the latest driver for my GPU fixed the problem for me
So I had it working at one point but its back to not working again ! I guess will have to wait until this is a bit more predictable haha 
hey at our studio we had simmilar issue, turns out lods are also changed a bit. So just incase before i send you down this path also look under your nanite setting for fallback relative error if you set this to 0 or closer to 0 your mesh wont get destroyed by nanite. The second thing we noticed was that the triangle reduction on the auto lod was extreemly aggressive. So right now you probably have auto lod checked. if you switch that to custom and go down to the section that says auto compute lod distances this should give you access to the pn triangle reduction on each mesh. Instead of doing 100 percent lod 0 50 percent lod 1 25 percent lod 2 exe try 100 - 80 - 70. and chance the screen percentages so the lods dont pop at 12 feet. So you may say what do lods have to do with nanite. They do effect nanite and still need to be setup correctly.
Also did the trick for me thanks, but raises another issue on my rig. Earlier I had intentionally changed from DX 12 to DX 11 for stability. For some reason I can’t work out UE5 & my RTX 3080 don’t play well together. I get GPU crashes with DX 12, but not with DX 11. Off topic, but would be interested to know if anyone else has run into a similar issue with UE5 & DX 12 0n their GPU?
If you’re on a 3000 series GPU and getting errors like gpu crashed or d3d device removed, try slightly underclocking your GPU or lowering the power target.
This worked for me, thank you
I have tried all the above fixes and verified my Windows, DX12, and GPU. The only difference is I am running on Nvidia Studio drivers. Not sure if that matters.
I can’t get the meshes to look even semi good relatively close and as it turns out I need it for cinematic usage. So I am really been banging my head against a wall here. New project with proper settings also doesn’t work.
Encounter same issue described before, nanite wasn´t working on UE5.0.2, tried updating windows 10 to 21H1 and switching to vulkan. It works now, I can see the nanite triangles but on the other hand FPS are reduced by half and Mesh complexity is just crazy bad, now all nanite meshes are red when before they were all green. Do you also have this problem? What is going on? I have RTX 3080 with lastest drivers.
I tried with Vulkan Dx12 dx11 and it doesn’t work at all since ue5 update.
I reinstalled the nvidia driver and nothing changed.
I will have to wait for the next update.
When I activate nanite it makes the object disappear and even a cube of 6 polygons and when redeactivate it no longer comes to normal, I have to re-import.
It was working fine before the update.
I can confirm that in UE5.02 in vulkan mode nanite works.
Create a third person project. search for RHI and set it to vulkan.
Enable nanite for the objects in the scene (you do that in the content browser)
Switch the viewport mode to nanite. everything works.
Warning it takes like forever because the editor will calculate a bunch of shaders every time you do the steps above.
I suggest leaving it be to finish the shader compilation each time. So switch to vulkan restart, leave the editor do its thing.
then enable nanite for the ramp, cylinder and whatever in the LevelPrototyping folder. (leave the chamfer cube alone)
editor will recompile shaders, leave it be.
After that it works
Issue here was forward rendering being enabled. If you’re working on a VR game, this was likely the problem
Thanks, it worked! The only issue with r.Nanite.RequireDX12=0 that it will recompile shaders every time I open a project( Is it supposed to do so?
I have seen the same behavior in my tests, but I don’t have any solutions for that at this time. Since this workaround for the Windows version problem is not supported, it’s best to migrate the VMs to 2022 at your earliest convenience.
I gave Vulkan a shot but then noticed that I couldn’t use any of the hardware raytracing capabilities of the engine which for me was a no go. On top of that nanite wasn’t as effective, with meshes becoming more noticeably changed with distance. The sudden popping in and out was distracting and made everything feel more like a typical LOD system rather than the smooth and gradual transitions we are used to seeing with Nanite in DX12.
And at some point I tried the DX11 thing too like some people here suggested, but the results were very unstable. I either had to recompile the shaders more than once or Nanite view would randomly stop working. Sometimes there was also a flickering problem with the meshes that I’ve never seen before.
Taking into consideration what some others have said about the DX11 solution, it could be problematic since there’s no way of knowing if this dependency would interfere with other functions in future updates. The fact that Nanite has also supposedly been optimized to work better with DX12 made me feel like I would be missing out on something.
Anyway after dealing with this issue for so long I found that updating windows 10 and also reinstalling previous windows updates resulted in Nanite finally working for me. Prior to this no other solution really helped me at all unfortunately.