FLUX UNETLoader: 'NoneType' object has no attribute 'lower'

[BrechtCorbeel]

Expected Behavior

Run the workflow

Actual Behavior

throw the error

Steps to Reproduce

Using a workflow at the Load Difussion Stage

Debug Logs

Error occurred when executing UNETLoader:

'NoneType' object has no attribute 'lower'

  File "W:\smatrix\Data\Packages\ComfyUI\execution.py", line 152, in recursive_execute
    output_data, output_ui = get_output_data(obj, input_data_all)
  File "W:\smatrix\Data\Packages\ComfyUI\execution.py", line 82, in get_output_data
    return_values = map_node_over_list(obj, input_data_all, obj.FUNCTION, allow_interrupt=True)
  File "W:\smatrix\Data\Packages\ComfyUI\execution.py", line 75, in map_node_over_list
    results.append(getattr(obj, func)(**slice_dict(input_data_all, i)))
  File "W:\smatrix\Data\Packages\ComfyUI\nodes.py", line 836, in load_unet
    model = comfy.sd.load_unet(unet_path, dtype=dtype)
  File "W:\smatrix\Data\Packages\ComfyUI\comfy\sd.py", line 626, in load_unet
    sd = comfy.utils.load_torch_file(unet_path)
  File "W:\smatrix\Data\Packages\ComfyUI\comfy\utils.py", line 14, in load_torch_file
    if ckpt.lower().endswith(".safetensors") or ckpt.lower().endswith(".sft"):

Other

No response