I'm in the city Cephallenia on Corellia, where I was hoping to get transported via NPC service. However, when I try to talk to an NPC that does transport, no text comes up. The buttons are there for me to choose a response, but there is no dialouge. I thought it was just my computer until I talked to one of the "Beware of Creatures" NPCs, and I didn't encounter the same problem.
As far as I know there might be two explanations for your problem.
1) It is a bug and you should report it.
2) It may be that the browser that you are using isn't fully compatible with SWC, so it might not display everything correctly (firefox works best with SWC).
My suggestion would be to try to find another transport NPC if you can. However if you really need transport try asking a player to transport you or a faction member if you are a part of a faction.
If the NPC was owned by a PC it may not function as expected, report the NPC's identity (Name and ID if you have it), then look to see if there is another of the same type around. Likely near or in the starport.
Warning this is strictly Orions McPhees Opinion, it may or may not have any bearing on events true or imagined