Can not save my model after Editing

[WispY]

I have created... some Weapon model and I wanted to add the effect of standart war3 arrow in Magos Model Editor (white line after the arrow when it moves)
So I have copied Ribbon Stats from arror to my model, but when I try to save my model I get message...
Unable to save "E:\...\PencilTowerBullet", unknown extention ""!
What is wrong to me?
And... can you explain how to copy Ribbon and Particle effects from one model to other?

And if I Remove the Ribbon that I have created, that error with saving stays... (that is very O_O to me, because ussualy when guy deletes the sourse of the problem, it goes away)

 

[Devine]

If you opened an mdl model, save it as PencilTowerBulle.mdl
If you opened an mdx model, save it as PencilTowerBulle.mdx

 

[WispY]

Hahahaha! Omg, I have noticed that I am awful noob
Thanks!