Saving your scene before rendering is crucial. If you haven't, then it's a lesson in the importance of backing up your work. Should you need to begin anew, you can reload the scene into Poser. Overloading your scene with figures can lead to rendering issues. Consider that each character's clothing counts as separate figures. With 12 characters dressed in tops and bottoms, you're essentially trying to render 36 figures, excluding hair. To manage this, you could either use billboard figures for the background or render in layers and composite in an application like Photoshop. Each section would still need to be rendered separately for later composition. Another strategy is to reduce file size overhead by using low-resolution textures and figures as background fillers. Implementing these methods requires careful planning and meticulous rendering for a satisfactory outcome. By the way, you didn't specify which rendering engine you're using.