(quick fix) WindowsError: [Error 2] The system cannot find the file specified

[iobataya]

This issue may be Windows-specific. During MolViewer.start(), the error above pops up. It seemd that the OS cannot find a file for a command dir for its shell, but it fails.

This can be fixed quickly by adding shell=True for subprocess.Popen

self._process = subprocess.Popen([exe, "-R"] + list(args), shell=True)

I hope this helps. I really appreciate your project ;-)