There are various problem with today’s in-game patch.
– Some members are reporting they’re not in the guild.
– Some members reporting unable to chat.
– Guild build queue is broken.
– Switching out of guild chat window makes guild chat disappear.
– Switching to another zone wipes guild chat.
6 MAR 2015: If you are having problems using guild chat, try pressing “y”, to the left of your account name is a drop-down box. Change yourself to Invisible, then back to Online.
For up-to-date info on bug fixes, reference: http://wiki.guildwars2.com/wiki/Patch