IndexError: list index out of range

[heavens77543]

    elif m in {ACmix}:
        c1, c2 = ch[f], args[0]
        args = [c1, c2, 7, 4, *args[1:]]

IndexError: list index out of range

File "D:\anaconda3202210\envs\yolov7\lib\site-packages\ultralytics\nn\tasks.py", line 990, in parse_model
c1, c2 = ch[f], args[0]
IndexError: list index out of range