Bug 320285 Messages inteneded for developers in the error log
The message "unsupported: isEditorAreaVisible" appears in the error log during the normal run of e4 SDK. (For instance, starting the e4 SDK on an clean workspace produces two of those messages.)
bundles/org.eclipse.e4.ui.workbench/src/org/eclipse/e4/ui/internal/workbench/ModelServiceImpl.java
win.setToBeRendered(false);
		}
		
		List<MTrimBar> bars = findElements(window, null, MTrimBar.class, null);
		List<MToolControl> toRemove = new ArrayList<MToolControl>();
		for (MTrimBar bar : bars) {
			for (MUIElement barKid : bar.getChildren()) {
				if (!(barKid instanceof MToolControl))
					continue;
				String id = barKid.getElementId();
				if (id != null && id.contains(persp.getElementId())) {
					toRemove.add((MToolControl) barKid);
				}
			}
		}
		for (MToolControl toolControl : toRemove) {
			
			if (toolControl.getObject() != null
					&& toolControl.getObject().getClass().getName().contains("TrimStack")) { 
				IEclipseContext ctxt = EclipseContextFactory.create();
				ctxt.set("show", false); 
				ContextInjectionFactory.invoke(toolControl.getObject(), Execute.class, ctxt);
			}
			toolControl.setToBeRendered(false);
			toolControl.getParent().getChildren().remove(toolControl);
		}