PythonMode Error:cannot start python sketch service

system information : Windows 10 (x64) - Processing 3.5.4 - Python Mode for Processing 3 3063 I install Python Mode through the “add mode” menu , but after installed, everytime I try to change to Python mode, a window throw out with “PythonMode Error:cannot start python sketch service”, I found the err file in %APPDATA%\Processing\console, below is the content: could not create registry; assume it's already created Exception in thread "Contribution List Downloader" java.lang.NullPointerException at processing.app.contrib.ContributionListing.countUpdates(ContributionListing.java:516) at processing.app.contrib.ContributionListing$1$1.run(ContributionListing.java:400) at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:301) at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758) at java.awt.EventQueue.access$500(EventQueue.java:97) at java.awt.EventQueue$3.run(EventQueue.java:709) at java.awt.EventQueue$3.run(EventQueue.java:703) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74) at java.awt.EventQueue.dispatchEvent(EventQueue.java:728) at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:205) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:109) at java.awt.WaitDispatchSupport$2.run(WaitDispatchSupport.java:190) at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:235) at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:233) at java.security.AccessController.doPrivileged(Native Method) at java.awt.WaitDispatchSupport.enter(WaitDispatchSupport.java:233) at java.awt.Dialog.show(Dialog.java:1084) at javax.swing.JOptionPane.showOptionDialog(JOptionPane.java:869) at javax.swing.JOptionPane.showMessageDialog(JOptionPane.java:666) at javax.swing.JOptionPane.showMessageDialog(JOptionPane.java:637) at processing.app.Messages.showError(Messages.java:147) at jycessing.mode.run.SketchServiceManager.start(Unknown Source) at jycessing.mode.PythonMode.createEditor(Unknown Source) at processing.app.Base.handleOpen(Base.java:1360) at processing.app.Base.handleOpen(Base.java:1314) at processing.app.Base.handleNew(Base.java:1216) at processing.app.Base.changeMode(Base.java:1001) at processing.app.ui.Editor$8.actionPerformed(Editor.java:542) at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022) at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2348) at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402) at javax.swing.JToggleButton$ToggleButtonModel.setPressed(JToggleButton.java:308) at javax.swing.AbstractButton.doClick(AbstractButton.java:376) at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:842) at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(BasicMenuItemUI.java:886) at java.awt.Component.processMouseEvent(Component.java:6539) at javax.swing.JComponent.processMouseEvent(JComponent.java:3324) at java.awt.Component.processEvent(Component.java:6304) at java.awt.Container.processEvent(Container.java:2239) at java.awt.Component.dispatchEventImpl(Component.java:4889) at java.awt.Container.dispatchEventImpl(Container.java:2297) at java.awt.Component.dispatchEvent(Component.java:4711) at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4904) at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4535) at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4476) at java.awt.Container.dispatchEventImpl(Container.java:2283) at java.awt.Window.dispatchEventImpl(Window.java:2746) at java.awt.Component.dispatchEvent(Component.java:4711) at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:760) at java.awt.EventQueue.access$500(EventQueue.java:97) at java.awt.EventQueue$3.run(EventQueue.java:709) at java.awt.EventQueue$3.run(EventQueue.java:703) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:84) at java.awt.EventQueue$4.run(EventQueue.java:733) at java.awt.EventQueue$4.run(EventQueue.java:731) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74) at java.awt.EventQueue.dispatchEvent(EventQueue.java:730) at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:205) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116) at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93) at java.awt.EventDispatchThread.run(EventDispatchThread.java:82) jycessing.mode.run.RMIUtils$RMIProblem: java.rmi.ConnectException: Connection refused to host: 127.0.0.1; nested exception is: java.net.ConnectException: Connection refused: connect at jycessing.mode.run.RMIUtils.bind(Unknown Source) at jycessing.mode.run.SketchServiceManager.start(Unknown Source) at jycessing.mode.PythonMode.createEditor(Unknown Source) at processing.app.Base.handleOpen(Base.java:1360) at processing.app.Base.handleOpen(Base.java:1314) at processing.app.Base.handleNew(Base.java:1216) at processing.app.Base.changeMode(Base.java:1001) at processing.app.ui.Editor$8.actionPerformed(Editor.java:542) at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022) at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2348) at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402) at javax.swing.JToggleButton$ToggleButtonModel.setPressed(JToggleButton.java:308) at javax.swing.AbstractButton.doClick(AbstractButton.java:376) at javax.swing.plaf.basic.BasicMenuItemUI.doClick(BasicMenuItemUI.java:842) at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(BasicMenuItemUI.java:886) at java.awt.Component.processMouseEvent(Component.java:6539) at javax.swing.JComponent.processMouseEvent(JComponent.java:3324) at java.awt.Component.processEvent(Component.java:6304) at java.awt.Container.processEvent(Container.java:2239) at java.awt.Component.dispatchEventImpl(Component.java:4889) at java.awt.Container.dispatchEventImpl(Container.java:2297) at java.awt.Component.dispatchEvent(Component.java:4711) at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4904) at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4535) at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4476) at java.awt.Container.dispatchEventImpl(Container.java:2283) at java.awt.Window.dispatchEventImpl(Window.java:2746) at java.awt.Component.dispatchEvent(Component.java:4711) at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:760) at java.awt.EventQueue.access$500(EventQueue.java:97) at java.awt.EventQueue$3.run(EventQueue.java:709) at java.awt.EventQueue$3.run(EventQueue.java:703) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:84) at java.awt.EventQueue$4.run(EventQueue.java:733) at java.awt.EventQueue$4.run(EventQueue.java:731) at java.security.AccessController.doPrivileged(Native Method) at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74) at java.awt.EventQueue.dispatchEvent(EventQueue.java:730) at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:205) at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116) at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101) at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93) at java.awt.EventDispatchThread.run(EventDispatchThread.java:82) Caused by: java.rmi.ConnectException: Connection refused to host: 127.0.0.1; nested exception is: java.net.ConnectException: Connection refused: connect at sun.rmi.transport.tcp.TCPEndpoint.newSocket(TCPEndpoint.java:619) at sun.rmi.transport.tcp.TCPChannel.createConnection(TCPChannel.java:216) at sun.rmi.transport.tcp.TCPChannel.newConnection(TCPChannel.java:202) at sun.rmi.server.UnicastRef.newCall(UnicastRef.java:338) at sun.rmi.registry.RegistryImpl_Stub.bind(RegistryImpl_Stub.java:60) ... 46 more Caused by: java.net.ConnectException: Connection refused: connect at java.net.DualStackPlainSocketImpl.connect0(Native Method) at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:79) at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350) at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206) at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188) at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172) at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392) at java.net.Socket.connect(Socket.java:589) at java.net.Socket.connect(Socket.java:538) at java.net.Socket.<init>(Socket.java:434) at java.net.Socket.<init>(Socket.java:211) at jycessing.mode.run.RMIUtils$1.createSocket(Unknown Source) at sun.rmi.transport.tcp.TCPEndpoint.newSocket(TCPEndpoint.java:613) ... 50 more D:\Green\processing\modes\PythonMode\formatter\pep8.py:100: FutureWarning: Possible nested set at position 1 EXTRANEOUS_WHITESPACE_REGEX = re.compile(r'[[({] | []}),;:]') how to fix it

[ljhui]

I have figure out it, it causes by my /etc/hosts file.

[rric]

Update: turning off the computer, and turning on again sometimes helps. Hm.