I started my project using Mecanim animation system. But I can see, that ORK is much more suited to Legacy system, so I decided to switch to Legacy while I'm not too far in development. To be fair, I've no experience using Legacy, but it seemed pretty straightforward - I switched all my animations to Legacy and my character model rigs to Legacy too. I remade ORK setup according to tutorial and nothing works - my characters still moves only in T pose. I then downloaded Ybot from mixamo, which is Mecanim rigged too. Switched it to legacy, used same animations - and it works perfectly. Ybot and my characters setup is identical, everything is the same, but my characters floats only in T pose, while Ybot is animated. Anybody knows why is that? Or some models simply can not be converted to legacy?
Also, by my models I mean models that I bought, not modeled myself.