Open .cdm or .scn file. The exception relates to a null pointer when opening the outline view.
For example:
java.lang.NullPointerException
at org.eclipse.ui.part.PageBook.showPage(PageBook.java:95)
at org.pi4soa.designer.editor.ChoreographyDescriptionEditor$OutlinePage.createControl(ChoreographyDescriptionEditor.java:1102)
at org.eclipse.ui.views.contentoutline.ContentOutline.doCreatePage(ContentOutline.java:137)
at org.eclipse.ui.part.PageBookView.createPage(PageBookView.java:408)
at org.eclipse.ui.part.PageBookView.partActivated(PageBookView.java:751)
at org.eclipse.ui.part.PageBookView$4.partActivated(PageBookView.java:1014)