What happened to formulaxl_v10 model? I can't find it anymore.

Been using this model which was awesome for posters. Today tried to download it again to a new PC but can't find it.

Not sure what model you're looking for, but there is one model called FormulaXL: https://civitai.com/models/129922/formulaxl-xl-comfyui

If this is not model you're looking for, models can be removed by author (for different reasons), and can be removed by moderators for violating CivitAI ToS.