Red light is an indication that Rollo has a problem with your label.
Most likely, Rollo needs to re-learn your label.
Please ensure there are multiple labels available to Rollo and then run the automatic label identification. Simply press and hold the top circular button on Rollo until you hear one beep. Rollo will then move labels back and forth to learn the gap and other properties of your labels.
To watch this in a video, please see: Setup Rollo for First Use
If automatic label identification does not work or red light remain, please turn off Rollo by using the power switch on the back and turn the unit back on.