AttributeError: module 'open3d.open3d.visualization' has no attribute 'io'
# Solved by installing the latest version
$ pip3 install open3d --upgrade
# Checking the version (25/04/2022)
$ python3
Python 3.7.5 (default, Dec 9 2021, 17:04:37)
[GCC 8.4.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import open3d as o3d
>>> o3d.__version__
'0.15.2'