If I have a grey question mark above me when you visit me, it means you already have an uncompleted assignment - you must finish the previous assignment I gave you before I will give you new ones.
If I don't have any symbols (question marks or exclamation marks) above my head when you visit - there may have been a small bug - just contact our support team and they will set you back on the right path. You can send them an email to support@wizard101.com