No module named 'model'

[nimadindar]

Hi,
I tried to run CenterNet-master but I get the error 'ModuleNotFoundError: No module named 'model'' while running demo.py file.
This issue happens in /CenterNet-master/lib/roi_layers/nms.py, line 3 "from model import _C".
I can't find a solution to this problem.

[nimadindar]

I solved the mentioned problem but yet I get another one :
ImportError: cannot import name 'C' from 'lib.model' (E:\Object-Detection-for-Graphical-User-Interface\CenterNet-master\lib\model_init.py)
How can I solve this one?