Cloning T2DStaticSprite

I want to clone T2DStaticSprite object basing on a material having image mode "cell".

I marked this object as template.

As soon as i use "Clone()" I get an assert failure when i start the game.

The failure says:
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T2DStaticSprite.CopyTo(TorqueObject obj) needs the following lines of code:

T2DStaticSprite obj2 = (T2DStaticSprite)obj;
obj2.MaterialRegionIndex = MaterialRegionIndex;
...
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The same thing is working as soon as i have image mode"FULL".

In easy words:

I have an object basing on a material with more sprites in it.
I clone it.
I get this message as soon as i run the code.

I change the material to a material which has only one sprite, it works

Thanks for any help.