title: Intellij not recognising xml for bpmn
body: <p>This just started to happen out of no where.  I have an existing Activiti project.   I have the Activiti BPMN Visualizer plugin installed. Now in every one of my .bpmn20.xml files, Idea is saying &quot;element x must be declared&quot;  or &quot;cannot resolve symbol&quot;  Here is an example:</p>
  <pre><code>&lt;?xml version=&quot;1.0&quot; encoding=&quot;UTF-8&quot;?&gt;
  &lt;definitions xmlns=&quot;http://www.omg.org/spec/BPMN/20100524/MODEL&quot; xmlns:xsi=&quot;http://www.w3.org/2001/XMLSchema-instance&quot;
           xmlns:xsd=&quot;http://www.w3.org/2001/XMLSchema&quot; xmlns:activiti=&quot;http://activiti.org/bpmn&quot;
           xmlns:bpmndi=&quot;http://www.omg.org/spec/BPMN/20100524/DI&quot;
           xmlns:omgdc=&quot;http://www.omg.org/spec/DD/20100524/DC&quot; xmlns:omgdi=&quot;http://www.omg.org/spec/DD/20100524/DI&quot;
           typeLanguage=&quot;http://www.w3.org/2001/XMLSchema&quot; expressionLanguage=&quot;http://www.w3.org/1999/XPath&quot;
           targetNamespace=&quot;http://www.activiti.org/processdef&quot;&gt;
  &lt;process id=&quot;test&quot; name=&quot;test&quot; isExecutable=&quot;true&quot;&gt;
  &lt;/process&gt;
  &lt;bpmndi:BPMNDiagram id=&quot;BPMNDiagram_test&quot;&gt;
      &lt;bpmndi:BPMNPlane bpmnElement=&quot;test&quot; id=&quot;BPMNPlane_test&quot;&gt;
      &lt;/bpmndi:BPMNPlane&gt;
  &lt;/bpmndi:BPMNDiagram&gt;
  &lt;/definitions&gt;
  </code></pre>
  <p>the tags for definitions and process are showing red,  with errors in the problems tab.  The namespaced tags, bpmndi:BPMNDiagram  for example,  are fine.  What has happened and how do I fix it?</p>