UPDATE - I have found the cause of the bug. When I enter fullscreen while the game is loading the world it causes it. I've added a forced crash report and the lod date of the game.
[media][media]I have restarted the game and created a new world, but the bug seems to have vanished. I don't know what caused it but I'll report back if it happens again.
Thanks for now.
I have attached the log from the game, although the bug didn't appear. There was no sign of it in the game.
I am out at the moment, I'll get back to you when I'm home. Sorry for the wait.
Here's the crash report you asked for. Hope it helps.
I'll just have to remember not to do that then. Thanks for your help anyway.