Guild raids.

Ozymandias
Relevant Patch Notes:
Guild Halls: Members cannot deploy squads to hall if under attack
does, this only mean you cannot guard? it looks, like you cannot recall and create, a new, squad in the hall. so i guess, you have to jump to closes quick travel point and run there as defender?

Yes, defenders will need to enter from a nearby quick travel point as well if the hall is under attack.