Using Lockup Table n-D with vector variable cause dimension error

I use a variable n[] for the table data and t[] as Breakpoints.

However if n and t only have one entry following error accours:

Dimension 1 of the table in block 'block' has a size of 1. Each tabledimension must have at least 2 elements.

i.e.

n = [10] and t = [0] creates the error.

n = [10 20] and t = [0 1] works just fine.

n and t are specified in a script.