Becoming a picky eater

Has anyone else's little one suddenly become picky with solids. At first with weaning he would pretty much eat anything I gave him but the last two weeks he has become really picky. He's good with breakfast but he's gone off so many foods he used to like. He's never been good with just boiled veges or meat but basically anything else he would eat now he really only will eat yoghurt and avocado. Has anyone else had a previously good eater that's become picky and has it gone away again or did you do anything to help?