How are you loading the model in ComfyUI?
The official node doesn't support it yet and I couldn't find any custom node for it either.
Are you using any custom scripts? If yes, can you please share them as well?
Official node? Are you talking about the original BF16 model uploaded by Comfy-Org or this DF11 version?
For the original BF16 safetensors file, you simply need to update ComfyUI and it will work. This is the PR that adds support specifically for the XL model: https://github.com/Comfy-Org/ComfyUI/pull/13317/changes. You simply need to swap out the smaller non-XL model for the XL version.
But for this DF11 model, you need to update both ComfyUI and my DFloat11 custom node (you can find my custom node in the manager, called ComfyUI DFloat11 Extended). Then you need to replace the stock "Load Diffusion Model" node with my "DFloat11 Model Loader" node, and it should work.
Please let me know if you still experience any issues.
If you prefer to use the native node, comfyui uploaded the xl checkpoint here https://huggingface.co/Comfy-Org/ace_step_1.5_ComfyUI_files/blob/main/split_files/diffusion_models/acestep_v1.5_xl_turbo_bf16.safetensors
Thank you @mingyi456 and @Taithrah , for some reason my ComfyUI didn't update properly even through the .bat file, even though I used nightly update, so I manually updated the relevant files and it works now! 😄