It sounds like an issue with the client timing out while the zone is loading. I've spoken with someone in my guild who runs Poets Palace at least once a week and they said they always have to click the mirror twice to get in.
So, in the meantime it should be possible to get in, just try again after you timeout. I'll make sure we have it in the list of things to look into on our end.
LINK
(Rothgar) Re:Poet's Palace Crashing......
