I tried two npc conversations. A mystery mage and a storehouse container. In both conversations the dialog starting looping and you could not exit the loop. I had to quit the game to continue on.
There is an issue with Harvesting and some other activities when using the Windows client. A patch is building to fix the error, and should be available this afternoon. Updates | Shroud of the Avatar This includes speaking to NPC's. We will have to wait until a patch.