Matlab doc command not working: Error using doc>displayDocPage (line 171)

3 次查看（过去 30 天）

显示更早的评论

rickert 2018-11-6

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/428384-matlab-doc-command-not-working-error-using-doc-displaydocpage-line-171

评论： Akshay Khadse 2018-11-19

在 MATLAB Online 中打开

The doc command in my Matlab R2018B (relatively fresh) install on Windows 10 64bit is not working anymore.

When I type doc and some command, the following shows:

>> doc abs
Error using doc>displayDocPage (line 171)
Java exception occurred:
java.lang.NullPointerException
  at com.mathworks.help.helpui.DocRoot.buildUrl(DocRoot.java:197)
  at com.mathworks.help.helpui.DocRoot.buildUrl(DocRoot.java:186)
  at com.mathworks.help.helpui.DocRoot.buildDocSetItemUrl(DocRoot.java:59)
  at com.mathworks.mde.help.DocCommandHelpBrowserTask.getUrlToDisplay(DocCommandHelpBrowserTask.java:42)
  at com.mathworks.mde.help.JsHelpBrowser.doHelpBrowserTask(JsHelpBrowser.java:242)
  at com.mathworks.mde.help.JsHelpBrowser.doHelpBrowserTask(JsHelpBrowser.java:238)
  at com.mathworks.mde.help.JsHelpBrowser.showReferencePage(JsHelpBrowser.java:122)
  at com.mathworks.mlservices.MLHelpServices.showReferencePage(MLHelpServices.java:199)
Error in doc (line 125)
    if ~displayDocPage(possibleTopics) && ~showHelpwin(topic)
>>

And when I just call doc, an empty doc window pops up, and the following error shows in the command window:

>> doc
Exception in thread "AWT-EventQueue-0": java.lang.NullPointerException
  at com.mathworks.mlwidgets.help.DocConfigUrlBuilder.getUrlForDocConfig(DocConfigUrlBuilder.java:29)
  at com.mathworks.mlwidgets.help.LightweightHelpPanel.getNavigationUrl(LightweightHelpPanel.java:280)
  at com.mathworks.mlwidgets.help.LightweightHelpPanel.setCurrentLocation(LightweightHelpPanel.java:178)
  at com.mathworks.mde.help.JsHelpBrowserClient.setCurrentLocation(JsHelpBrowserClient.java:196)
  at com.mathworks.mde.help.JsHelpBrowserClient.showClient(JsHelpBrowserClient.java:234)
  at com.mathworks.mde.help.JsHelpBrowser$OpenInNewBrowser.openBrowser(JsHelpBrowser.java:345)
  at com.mathworks.mde.help.JsHelpBrowser$JsHelpBrowserRunnable.createAndShowBrowser(JsHelpBrowser.java:297)
  at com.mathworks.mde.help.JsHelpBrowser$JsHelpBrowserRunnable.run(JsHelpBrowser.java:292)
  at java.awt.event.InvocationEvent.dispatch(Unknown Source)
  at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
  at java.awt.EventQueue.access$500(Unknown Source)
  at java.awt.EventQueue$3.run(Unknown Source)
  at java.awt.EventQueue$3.run(Unknown Source)
  at java.security.AccessController.doPrivileged(Native Method)
  at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(Unknown Source)
  at java.awt.EventQueue.dispatchEvent(Unknown Source)
  at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
  at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
  at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
  at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
  at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
  at java.awt.EventDispatchThread.run(Unknown Source)
>>

The help function is working fine. How can I solve this problem?

4 个评论
显示 2更早的评论隐藏 2更早的评论

rickert 2018-11-7

Turning off the firewall and restarting Windows did not resolve the issue (while connected to VPN)

Akshay Khadse 2018-11-19

Since you are able to access the documentation without VPN, it seems to me that your institution has a firewall behind the VPN which might be blocking the connections. You could contact your network administrators to confirm the same and seek a resolution.

请先登录，再进行评论。

请先登录，再回答此问题。