Install Plugin is not working

Hi there and muchos kudos for fman !
I installed the 1.7.3 version
I cannot installed any plugins...
with the following error message
thanks for your help

(note : I replaced my current windows profile name with 'xxxxxxxx'

Command 'InstallPlugin' raised error.

Traceback (most recent call last):
  File "fman\impl\plugins\command_registry.py", line 66, in _execute_command
  File "C:\Users\xxxxxxxx\AppData\Local\fman\Versions\1.7.3\Plugins\Core\core\commands\__init__.py", line 1408, in __call__
    plugin_dir = self._install_plugin(repo.name, zipball_contents)
  File "C:\Users\xxxxxxxx\AppData\Local\fman\Versions\1.7.3\Plugins\Core\core\commands\__init__.py", line 1443, in _install_plugin
    dir_in_zip, = iterdir(zip_url)
  File "fman\impl\plugins\mother_fs.py", line 257, in __next__
  File "fman\impl\plugins\mother_fs.py", line 238, in get_next
  File "fman\impl\plugins\plugin.py", line 365, in iterdir
  File "C:\Users\xxxxxxxx\AppData\Local\fman\Versions\1.7.3\Plugins\Core\core\fs\zip.py", line 61, in iterdir
    for file_info in self._iter_infos(path):
  File "C:\Users\xxxxxxxx\AppData\Local\fman\Versions\1.7.3\Plugins\Core\core\fs\zip.py", line 230, in _iter_infos
    with _7zip(args, kill=True) as process:
  File "C:\Users\xxxxxxxx\AppData\Local\fman\Versions\1.7.3\Plugins\Core\core\fs\zip.py", line 442, in __enter__
    self._process = cls(self._args, self._cwd)
  File "C:\Users\xxxxxxxx\AppData\Local\fman\Versions\1.7.3\Plugins\Core\core\fs\zip.py", line 496, in __init__
    super().__init__(args, cwd, env, startupinfo=self._get_startupinfo())
  File "C:\Users\xxxxxxxx\AppData\Local\fman\Versions\1.7.3\Plugins\Core\core\fs\zip.py", line 485, in __init__
    cwd=cwd, env=env, **kwargs
  File "subprocess.py", line 709, in __init__
  File "subprocess.py", line 997, in _execute_child
FileNotFoundError: [WinError 2] The system cannot find the file specified

Start with core/commands/init.py around _install_plugin and core/fs/zip.py around iterdir, _iter_infos, and _7zip, following the traceback from InstallPlugin. Reproduce plugin installation on Windows 1.7.3 and inspect the WinError 2 failure. Done means installing a plugin no longer raises this missing-file error.