How to fix -Djava.endorsed.dirs not supported, that emerged after installing WTP in Eclipse?

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To fix this bug, you need to install/update the Eclipse Web Tools Platform (WTP) to version 3.9.4 or later.

Select "Help > Install new Software..."

Select or add following URL: http://download.eclipse.org/webtools/repository/oxygen

Check Web Tools Platform (WTP) 3.9.4

Select "Next" and follow instructions

(Bug was reported to Eclipse here: https://bugs.eclipse.org/bugs/show_bug.cgi?id=533162)

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