update from their Facebook page:
Sad to say we have had to pull the show for 2021. The continued situation and uncertainty around Covid 19, we don't know how we could get 2000 visitors, exhibitors and members safely in a covid secure manner in to the Knavesmire stand. The rules are in flux and we could have got the show organised to face a local lockdown or change in the rules with no notice.
Too big a risk to ourselves, our visitors and the reputation of the show.