MATLAB: Am I not able to use the installed help documentation properly after update in MATLAB 9.6 (R2019a)

MATLAB

Whenever searching any keywords in Help Documentation, there is only empty page by just showing loading image permanently with the following error message in the MATLAB command window.
Exception in thread "com.mathworks.mlwidgets.help.messages.HelpSystemMessageChannel Message Channel Thread": java.lang.NullPointerException
    at com.mathworks.search.lucene.LuceneIndexUtils.indexContainsField(LuceneIndexUtils.java:75)
    at com.mathworks.helpsearch.DocSearchEngineFactory.createAutoSearchEngine(DocSearchEngineFactory.java:50)
    at com.mathworks.help.helpui.search.DocSearchHandler.doSearch(DocSearchHandler.java:59)
    at com.mathworks.help.helpui.search.DocSearchHandler.doSearch(DocSearchHandler.java:52)
    at com.mathworks.mlwidgets.help.messages.search.DocSearchMessageHandler.handleSearch(DocSearchMessageHandler.java:47)
    at com.mathworks.mlwidgets.help.messages.search.DocSearchMessageHandler.handle(DocSearchMessageHandler.java:41)
    at com.mathworks.mlwidgets.html.messages.BrowserMessageSubscriber$HelpMessageRunnable.run(BrowserMessageSubscriber.java:110)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:748)
The above same issue is also occurred when typing "docsearch plot" at the MATLAB prompt.

Best Answer

There is a bug in MATLAB 9.6 (R2019a) in using both the following 2 settings after installed any update in R2019a which was installed with "English" for "Windows display language".
1. Set "Language" as Languages with a non-latin character set like "Korean" in Preferences > Help
2. Set "Documentation Location" as "Installed locally" in Preferences > Help
To work around this issue, change the “Documentation Location” to “mathworks.com” from “Installed locally” in Preference > Help in MATLAB.
Or, go to http://kr.mathworks.com/help website from your browser and then change the country selection to like “한국 (한국어)” at the bottom.
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