java.lang.​NoClassDef​FoundError

I'm a novice learning MATLAB. My MATLAB version is 2015a.I've learned from the guide book that by inputing demos in the command window, I can get help on how to use MATLAB with demonstration. I did as I was told and then the screen displays some error codes. The followings are the screenshot. What should I do. Hoping for solution.

Error using demo (line 21)
Java exception occurred:
java.lang.NoClassDefFoundError: Could not initialize class com.mathworks.mlwidgets.help.ProductFilterModel$InstalledState

  at com.mathworks.mlwidgets.help.DocCenterProductPrefs.getSelectedProductsFromPref(DocCenterProductPrefs.java:47)

  at com.mathworks.mlwidgets.help.DocCenterProductPrefs.getProductFilterModel(DocCenterProductPrefs.java:33)

  at com.mathworks.mlwidgets.help.DocCenterDocConfigParams.<init>(DocCenterDocConfigParams.java:37)

  at com.mathworks.mlwidgets.help.DocCenterDocConfig.getLocalConfig(DocCenterDocConfig.java:77)

  at com.mathworks.mlwidgets.help.DocCenterDocConfig.getInstance(DocCenterDocConfig.java:65)

  at com.mathworks.mlwidgets.help.DocCenterUtils$DefaultDependencyProvider.getDocConfig(DocCenterUtils.java:310)

  at com.mathworks.mlwidgets.help.DocCenterUtils.getDocConfig(DocCenterUtils.java:166)

  at com.mathworks.mlwidgets.help.DocCenterUtils.getExamplesUrlForDemoCommand(DocCenterUtils.java:157)

  at com.mathworks.mde.help.DocCenterBrowserHandler.showDemos(DocCenterBrowserHandler.java:595)

  at com.mathworks.mde.help.DocCenterBrowserHandler.showDemos(DocCenterBrowserHandler.java:574)

  at com.mathworks.mde.help.HelpBrowserBridge.showDemos(HelpBrowserBridge.java:182)

  at com.mathworks.mlservices.MLHelpServices.showDemos(MLHelpServices.java:217)

[Sudipta]

Hi, I am also experiencing the same error message while trying to read a ros bag file. Can anyone tell me why is this? Thanks in advance.

Answer 1

[MBD4FUN]

If the problem persist even if you restart Matlab, try to do a fresh re-install of Matlab. Hope it helps!

Cheers,

MBD4FUN

[YinSi Zhang]

Thank you, mate. I will have a try.