Unicorn Hat hd help needed

Hi all, complete raspberry newbie here. I’m learning it along with my 8 year old daughter.
We have a unicorn hat hd and have installed the script from pimoroni but when I plug the unicorn hat in the screen goes black and I get a no signal error on the monitor. Then when I unplug the hat the pi reboots. Any help would be much appreciated!

You shouldn’t be plugging the hat (or indeed anything else aside from USB) into or out of the Pi when it’s powered on.

Shut it down, pull the power then connect it and start it up again and see if that helps.

What he said, that’s fine where USB devices are concerned but the GPIO header isn’t a hot plug interface. You want to power down, and remove power, before adding or removing hardware to the GPIO header. It needs to be connected on boot up to be detected and initialized properly.