Can't convert from 'Float Array' to 'Float Array'?

Here is the function:
Method AddInstance(mat:TMat4,animMatrix:Float[]=Null)

Where's the rest? :)

A little more code would be helpfull as that line didn't cause it per se, so I would guess that it is the call that causes the issue or some usage in the method.

you can for example not send something of float[,] or float[][] to that method

Whats the call look like?