MyEclipse + Pulse error : can not open any DOM document

ไม่สามารถเปิด DOM document ได้เลย ทั้ง XML และ HTML

An internal error occurred during: "HTML Syntax Validator".


loader constraint violation: when resolving overridden method "org.eclipse.wst.html.core.internal.document.DOMStyleModelImpl.internalCreateDocument()Lorg/w3c/dom/Document;" the class loader (instance of org/eclipse/osgi/internal/baseadaptor/DefaultClassLoader) of the current class, org/eclipse/wst/html/core/internal/document/DOMStyleModelImpl, and its superclass loader (instance of org/eclipse/osgi/internal/baseadaptor/DefaultClassLoader), have different Class objects for the type org/w3c/dom/Document used in the signature

An internal error occurred during: "XML Validator".


Provider org.apache.xalan.processor.TransformerFactoryImpl not found