redim array error....subscript out of range

i am enclosing a file ......in this file i set the contents of an array using the "array function".....which i think makes this a 1D array. But i want a 2D array so i then redim the array using

ReDim Preserve apndx_class_array(UBound(apndx_class_array), 2)

but something is wrong somewhere ....i get a subscript out of range error