How do you save triggers?

I am trying to make a automated door (like in star trek), but when I make the triggers and then press apply , then move onto my other trigger and then finish all of the triggers associated with the door all of the triggers disappear and I am left with just blocks saying trigger (the material).

How do I stop my triggers from disappearing?!?

Ensure that the select option down the right hand side is set to either groups or objects, not solids.

Sounds like “ignore groups” is turned on.

Turn it off.

So basically what IronPhoenix said, yes.

Ah thanks guys :]