It's probably me who is doing something wrong but...

[Charlevieve]

I've checked that the add on is enabled - and my zygor interface and arrow are gone and I am not sure how to make them come back.

[Zygor]

You should see a small "Z" button near your minimap. Clicking that will show/hide the guide viewer and arrow.

[ZG Support 1]

If you don't see the Z icon on the mini map you can type "/zygor show" without the quotes into the game chat and that will get it showing.