Upload a non SL Skeleton riged model via the uploader. (A model was sent to gltf@lindenlab.com ) .... then once in the world, click on the Animesh checkbox in the edit window. Watch as you mesh turns invisible... uncheck to see the mesh again. SEE included pictures. I expected the viewer to not allow me to upload the riged mesh as it had bones that where not named like the SL bones. however it did let me and it did show the mesh but when the animesh check box is checked then it goes invisible... and now I can not delete the mesh from the sim .... should have went to a sandbox.