Currently have no TV channels just a message on screen saying problem with signal and error code YVM302. Does anyone know how to rectify this.
A lot of the time, yes.
https://support.youview.com/youview-box/error-messages/fix-for-yvm302/
Adding to what @Lսkе says, one step not in the YouView help there is to try plugging the aerial directly into the TV, and seeing if things are OK there or not.
Matter of fact, that would always be my suggestion for the first thing to try, tells you if it’s the aerial or not, saves you agonising over box settings if it is.
And if you say “Aerial? What aerial?” we get there even quicker 😛