For me, I was running an Apple Airport Express not connected to the internet. After playing for days on end with the internet setting in my iPad 3 I decided to grab my kids iPad Mini and it worked fine on that iPad. So, I copied the exact internet settings and still nothing.
I decided to give up on my iPad 3 (which is starting to show its age) and switch with my kids. The speaker went out on my iPad 3 anyways and the processor is better on the iPad Mini than on mine anyways. So, fixed…sorta.