It's probably that you didn't apply the bones to your model correctly. Make sure you did this correctly, and re-export the model.

okay I already did it and I know where is the problem. At workshop requirements there were nothing about bones ( only on weapon model ) but then I assigned it to bones and said the same. But then I restarted Dota and tried it once more and it worked !! So there is a bug, when you export fails and then you export correctly without closing Dota ( or maybe only closing Workshop) it will give you the same error.

The dota compiler doesn't overwrite old files properly for me. I don't know if this is a universal problem but I have to save my file as a new name each time I compile. I just delete them all once I get it working. So if you have a problem and recompile, your problem is probably fixed, you're just looking at the old files.

yes this exactly happend to me everytime I made any mistake... I need to restart DotA :) but it helps me doing things correctly to save time ;)