https://forums.autodesk.com/t5/maya-forum/error-message-with-python-quot-openmaya-py-line-21-dll-load/m-p/7034011#M72221 <P>I was dealing with this error in the context of running a Maya sub process from a compiled Python application.</P><P>&nbsp;</P><P>What I found was that without&nbsp;'SYSTEMDRIVE': 'C:' in your os.environ, this error would happen. So when you call a subprocess from a compiled Python program, create a dictionary of the environment and pass that to the subprocess.</P><P>&nbsp;</P><P>Example:</P><P>&nbsp;</P><PRE>import getpass import&nbsp;winpaths import subprocess processEnvironment = { 'SYSTEMROOT': '%s' % str(winpaths.get_windows()), #'C:\\windows' 'USERNAME': '%s' % getpass.getuser(), 'PATH':'%s\\python;%s\\python\\com\\lib;%s\\python\\com\\lib\\PySide2;' % (com.forge.config.getToolRoot(), com.forge.config.getToolRoot(), com.forge.config.getToolRoot()), 'PYTHONPATH': '%s\\python;%s\\python\\com\\lib;%s\\python\\com\\lib\\PySide2' % (com.forge.config.getToolRoot(), com.forge.config.getToolRoot(), com.forge.config.getToolRoot()), 'QT_QPA_PLATFORM_PLUGIN_PATH': '%s\\python\\com\\lib\\PySide2\\plugins\\platforms' % com.forge.config.getToolRoot(), 'QTDIR': '%s\\python\\com\\lib\\PySide2' % com.forge.config.getToolRoot(), 'USERPROFILE': '%s' % str(winpaths.get_user_profile()), # 'C:\\Users\\userName' 'APPDATA': '%s' % str(winpaths.get_appdata()), # 'C:\\Users\\userName\\AppData\\Roaming' 'LOCALAPPDATA': '%s' % str(winpaths.get_local_appdata()), # 'C:\\Users\\userName\\AppData\\Local' 'TMP': '%s\\Temp' % str(winpaths.get_local_appdata()), # 'C:\\Users\\userName\\AppData\\Local\\Temp' 'TEMP': '%s\\Temp' % str(winpaths.get_local_appdata()), # 'C:\\Users\\userName\\AppData\\Local\\Temp' 'WINDIR': '%s' % str(winpaths.get_windows()), #'C:\\windows' 'SYSTEMDRIVE': '%s:' % str(winpaths.get_windows()).split(':')[0] # 'C:' } mayaProcess = subprocess.Popen( [ mayaPyPath.replace('/', '\\\\'), '%s/python/com/forge/maya/characterize.py' % com.forge.config.getToolRoot().replace('\\', '/'), self._preferences.activeBridge.sourceSkeletonPath, self._preferences.activeBridge.sourceCharacterDefinitionPath, 'sourceCharacter', sourceOutputPath ], env=processEnvironment, shell=True, stdout=subprocessLogHandle, stderr=subprocess.STDOUT ) mayaProcess.wait()</PRE><P>That totally solved the issue for me in this context. Posting it here because others may run into this.....</P><P>You can ignore all the Qt stuff in there - we are using the same PySide2 version external to Maya with Python 2.7.12 that is why those env variables are in there....</P><P>&nbsp;</P> Fri, 21 Apr 2017 18:08:05 GMT Anonymous 2017-04-21T18:08:05Z