OnlyBarnet is due to undergo some essential maintenance and as a result will need to go offline for a period of time while the work takes place. During this period the board will go through stages of being visible with posting disabled or completely offline with error messages displayed on your screen. If you are able to post, it is likely those posts will at some point disappear.
The upgrade will hopefully fix some issues with slow page loads, duplicate posts and give an improved experience. Just maybe, there might also be a "like" button on the way.