Compiler Error: Operation cannot operate on addresses from different interfaces

I am getting the following error from the HLS compiler when compiling for FPGA.

"Compiler Error: Operation cannot operate on addresses from different interfaces"

The compiler points to the first line in a function that looks like this

template<class T>
TensorXL<T>::TensorXL(const TensorXL<T> &A) //copy constructor
{
	t_numCols = A.t_numCols;
	t_numRows = A.t_numRows;
	transposed = A.transposed;
	for (unsigned i = 0; i < A.t_numRows; i++)
	{
		for (unsigned j = 0; j < A.t_numCols; j++)
		{
			matrix[i][j] = A.matrix[i][j];
		}
	}
	null = false;
}

What does this error mean? What limitation am I running into?

Thanks,

messn036