I have just built the armbot and am controlling it with the remote. Everything seems to work fine for a few seconds then the Touch LED sensor turns red and everything shuts down. I have to keep restarting to get it to work again but after a few seconds the sensor goes read again and it stops. What am I doing wrong?

See this video explaining the default functionality of the Touch LED:

If it is turning red without you touching it (and you have updated the firmware), then it sounds like you have a bad component. Contact Vex customer support.

So I think there are two parts to the issue you’re having.
Paul covered the first part with the default functionality of the touch LED sensor, but if you have the Color Sensor attached, you will want to watch the next video on the default functionality of the Color Sensor at
Here you will see that if the color sensor sees a red(ish) object (event in the distance) the robot will stop (and the Touch LED will turn red).
Try disconnecting or covering the Color Sensor and see if the behavior continues.