qbasic.hlp (Topic list)
Subscript out of range
An array element was referred to with a subscript that was
outside the dimensions of the array, or an element of an
undimensioned dynamic array was accessed. Check that the
array is dimensioned and check the bounds of the array.
 
You may also get this error if the array size exceeds 64K.
Reduce the size of the array.
 
ERR code: 9