I've encountered this a couple of times recently and both were due to references to children in the prompt. The first was a 'sexy young woman carrying a young child on her hip' and the second was a a woman swinging on a 'child's swing' in a playground. Removing the 'child's' solved the issue. So check the prompts to see if there is anything even remotely referencing children even if seems totally benign.

Edit: Forgot to add that the images will vanish from your own galleries as well as the Public gallery.