popup submenus aka section headers have internal path enabled by default
This goes against the documentation that says section headers should have internal paths disabled.
The error seems to lie on line 372 of of WMenu. I believe at this point you should call setInternalPathEnabled(false); on the newly created WMenuItem.
You can work around this error by calling subMenu.getParentItem().setInternalPathEnabled(false); after you have called parentMenu.addMenu("name",subMenu);
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