arduino mega 2560 and Glediator not working

Problem is that Glediator is a pile of crap. There are so many configuration options that don’t actually do anything or indeed work, that unless you have the near same setup as the author nothing works.

have connected the data pin to pin 6
the ground to ground on the arduino
and the power wires on the strip to a psu

But no resistor in the data line and no capacitor across the LED’s supply.