>>2884882Prichin etomu mozhet byt celaya kucha, bez pol-litra ne razobratsya. If it loads in MMD just fine, then you probably hid the material by accident. PMXView > F3 > MAT: A/Select all to check. You can also try hiding all materials and enabling them one by one to find out which one(s) contain(s) the joint meshes (if it's not clear from the naming), then checking the opacity of those materials. If that's not it, try checking the model for errors: PMXEditor > File > PMXInfo > uncheck the circle flag. There could be a missing texture. You can also try reverting the changes to see at which point the joints disappear, unless you've already exited the editor or reloaded the model, which would be a bad move.
If you can't solve it yourself, upload your edit to a site like litterbox.catbox.moe, selecting the 3 days expiration period before uploading.