设置数组值会导致Visual Basic中的Argument不可选错误

I am trying to set the values of an array of Collections inside a For loop. However, when I go to run the program, it throws a compile error that states "Argument not optional" and highlights the part where I set the array value. When I go to debug the subroutine, I cannot get past the first line of ConvertbucketCollectionTobucketArray(). At that point, bucketArray elements 0 through 12 have a value of Nothing and bucketCollection contains 13 elements(1-13), where only several contain items.I am trying to set the values of an array of Co