When using the Range node, if you send it a negative number for count, and ab, Vectorworks locks ups due to the creation of an endless loop. Eventually your computer will run out memory.
The node should probably test to make sure this doesn't happen.
I replaced the RunNode with the following to check for this:
def RunNode(self):
def frange(x, y, jump):
while x - y <= .000001:
yield x
x += jump
a = self.Params.start.value
b = self.Params.stop.value
c = self.Params.count.value
list = []
if ((c == 0) or (a < b and c < 0) or (a > b and c > 0)):
list = [a, b]
else:
c = (b - a) / c
list = [n for n in frange( a, b, c)]
self.Params.list.value = list