2009 Retune
The Freeview service underwent a major upgrade on 30 September 2009 which required 18 million households to retune their Freeview receiving equipment. The changes, meant to ensure proper reception of Channel 5, led to several thousand complaints from people who lost channels (notably ITV3 and ITV4) as a result of retuning their equipment. The Freeview website crashed and the call centre was inundated as a result of the problems.
The change involved an update to the NIT (Network Information Table), which some receivers could not accommodate. Many thousands of people could not receive some channels. This included 460,000 fed from relay stations who have permanently lost access to ITV3 and ITV4. Updates were broadcast to enable firmware changes, but in some cases the receiver must be left on and receiving broadcasts to accept the updates; not everyone was aware of this.
Read more about this topic: Freeview (UK)