When I try to open a .rb file include multibite charactor, I cannnot open it with these error messages. Encoding of files, workspace and project are UTF8. java.lang.IllegalArgumentException: Argument not valid at org.eclipse.swt.SWT.error(SWT.java:3547) at org.eclipse.swt.SWT.error(SWT.java:3481) at org.eclipse.swt.SWT.error(SWT.java:3452) at org.eclipse.swt.custom.StyledText.setStyleRanges(StyledText.java:7865) at org.eclipse.swt.custom.StyledText.setStyleRanges(StyledText.java:7959) at org.eclipse.jface.text.TextViewer.applyTextPresentation(TextViewer.java:4429) at org.eclipse.jface.text.TextViewer.changeTextPresentation(TextViewer.java:4481) at org.eclipse.jface.text.presentation.PresentationReconciler.applyTextRegionCollection(PresentationReconciler.java:580) at org.eclipse.jface.text.presentation.PresentationReconciler.processDamage(PresentationReconciler.java:569) at org.eclipse.jface.text.presentation.PresentationReconciler.access$3(PresentationReconciler.java:565) at org.eclipse.jface.text.presentation.PresentationReconciler$InternalListener.inputDocumentChanged(PresentationReconciler.java:119) at org.eclipse.jface.text.TextViewer.fireInputDocumentChanged(TextViewer.java:2685) at org.eclipse.jface.text.TextViewer.setDocument(TextViewer.java:2734) at org.eclipse.jface.text.source.SourceViewer.setDocument(SourceViewer.java:518) at org.eclipse.jface.text.source.projection.ProjectionViewer.setDocument(ProjectionViewer.java:370) at org.eclipse.jface.text.source.SourceViewer.setDocument(SourceViewer.java:473) at org.eclipse.ui.texteditor.AbstractTextEditor.initializeSourceViewer(AbstractTextEditor.java:3786) at org.eclipse.ui.texteditor.AbstractTextEditor.createPartControl(AbstractTextEditor.java:3332) at org.eclipse.ui.texteditor.StatusTextEditor.createPartControl(StatusTextEditor.java:53) at org.eclipse.ui.texteditor.AbstractDecoratedTextEditor.createPartControl(AbstractDecoratedTextEditor.java:378) at org.rubypeople.rdt.internal.ui.rubyeditor.RubyAbstractEditor.createPartControl(RubyAbstractEditor.java:341) at org.rubypeople.rdt.internal.ui.rubyeditor.RubyEditor.createPartControl(RubyEditor.java:355) at org.eclipse.ui.internal.EditorReference.createPartHelper(EditorReference.java:661) at org.eclipse.ui.internal.EditorReference.createPart(EditorReference.java:426) at org.eclipse.ui.internal.WorkbenchPartReference.getPart(WorkbenchPartReference.java:592) at org.eclipse.ui.internal.PartPane.setVisible(PartPane.java:299) at org.eclipse.ui.internal.presentations.PresentablePart.setVisible(PresentablePart.java:179) at org.eclipse.ui.internal.presentations.util.PresentablePartFolder.select(PresentablePartFolder.java:268) at org.eclipse.ui.internal.presentations.util.LeftToRightTabOrder.select(LeftToRightTabOrder.java:65) at org.eclipse.ui.internal.presentations.util.TabbedStackPresentation.selectPart(TabbedStackPresentation.java:400) at org.eclipse.ui.internal.PartStack.refreshPresentationSelection(PartStack.java:1256) at org.eclipse.ui.internal.PartStack.setSelection(PartStack.java:1209) at org.eclipse.ui.internal.PartStack.showPart(PartStack.java:1604) at org.eclipse.ui.internal.PartStack.add(PartStack.java:499) at org.eclipse.ui.internal.EditorStack.add(EditorStack.java:103) at org.eclipse.ui.internal.PartStack.add(PartStack.java:485) at org.eclipse.ui.internal.EditorStack.add(EditorStack.java:112) at org.eclipse.ui.internal.EditorSashContainer.addEditor(EditorSashContainer.java:63) at org.eclipse.ui.internal.EditorAreaHelper.addToLayout(EditorAreaHelper.java:217) at org.eclipse.ui.internal.EditorAreaHelper.addEditor(EditorAreaHelper.java:207) at org.eclipse.ui.internal.EditorManager.createEditorTab(EditorManager.java:774) at org.eclipse.ui.internal.EditorManager.openEditorFromDescriptor(EditorManager.java:673) at org.eclipse.ui.internal.EditorManager.openEditor(EditorManager.java:634) at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditorBatched(WorkbenchPage.java:2737) at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditor(WorkbenchPage.java:2651) at org.eclipse.ui.internal.WorkbenchPage.access$13(WorkbenchPage.java:2643) at org.eclipse.ui.internal.WorkbenchPage$10.run(WorkbenchPage.java:2595) at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:67) at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2590) at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2574) at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2565) at org.eclipse.ui.ide.IDE.openEditor(IDE.java:644) at org.eclipse.ui.ide.IDE.openEditor(IDE.java:603) at org.rubypeople.rdt.internal.ui.rubyeditor.EditorUtility.openInEditor(EditorUtility.java:83) at org.rubypeople.rdt.internal.ui.rubyeditor.EditorUtility.openInEditor(EditorUtility.java:70) at org.rubypeople.rdt.internal.ui.actions.OpenActionUtil.open(OpenActionUtil.java:19) at org.rubypeople.rdt.ui.actions.OpenAction.run(OpenAction.java:164) at org.rubypeople.rdt.ui.actions.OpenAction.run(OpenAction.java:148)