Published Monday, 21 November 2011
The actor was travelling from down from Yorkshire when he was involved in a smash.
Miller, who recently announced he is to leave the soap next year, was taken to hospital to treat his injuries, and was forced to pull out of the event as a result.
In a series of posts on his Twitter page, he writes: "Reading! I am so so sorry for not being there today. Truly. From the bottom of my heart! I've had a check up after the bump and everything's fine.
"Bit of swelling on my knee but nothing to worry about. I'll make it up to you somehow. I am so so sorry!!"
Actor Andy Beckwith stepped in to take Miller's place at the event at the last minute.