Key members of the AI research team behind Stable Diffusion, a text-to-image generation model, have resigned from Stability AI. Led by Robin Rombach, the team published a third edition of the model, combining diffusion structures and transformers. Stability AI has been hit by an exodus of executives and faces financial difficulties, with spending outstripping revenue. The company is also dealing with copyright infringement lawsuits and allegations of inappropriate activity from employees at rival AI image generation firm Midjourney. Stability AI, previously valued at $1 billion, is now struggling with significant challenges.