当我在插件中自动格式化（ctrl + shift + f）时，我得到以下异常：
!ENTRY org.apache.log4j 4 0 2016-10-13 00:30:23.002
!MESSAGE org.eclipse.xtext.ui.editor.formatting2.ContentFormatter$FormattingUnitOfWork - Error formatting platform:/resource/Test/src/algebra.mcrl2: null
!STACK 0
java.lang.IllegalStateException
at org.eclipse.xtext.formatting2.regionaccess.internal.NodeModelBasedRegionAccessBuilder.process(NodeModelBasedRegionAccessBuilder.java:223)
at org.eclipse.xtext.formatting2.regionaccess.internal.NodeModelBasedRegionAccessBuilder.process(NodeModelBasedRegionAccessBuilder.java:214)
at org.eclipse.xtext.formatting2.regionaccess.internal.NodeModelBasedRegionAccessBuilder.process(NodeModelBasedRegionAccessBuilder.java:214)
at org.eclipse.xtext.formatting2.regionaccess.internal.NodeModelBasedRegionAccessBuilder.process(NodeModelBasedRegionAccessBuilder.java:214)
at org.eclipse.xtext.formatting2.regionaccess.internal.NodeModelBasedRegionAccessBuilder.process(NodeModelBasedRegionAccessBuilder.java:214)
at org.eclipse.xtext.formatting2.regionaccess.internal.NodeModelBasedRegionAccessBuilder.process(NodeModelBasedRegionAccessBuilder.java:214)
at org.eclipse.xtext.formatting2.regionaccess.internal.NodeModelBasedRegionAccessBuilder.process(NodeModelBasedRegionAccessBuilder.java:214)
at org.eclipse.xtext.formatting2.regionaccess.internal.NodeModelBasedRegionAccessBuilder.process(NodeModelBasedRegionAccessBuilder.java:214)
at org.eclipse.xtext.formatting2.regionaccess.internal.NodeModelBasedRegionAccessBuilder.process(NodeModelBasedRegionAccessBuilder.java:214)
at org.eclipse.xtext.formatting2.regionaccess.internal.NodeModelBasedRegionAccessBuilder.process(NodeModelBasedRegionAccessBuilder.java:214)
at org.eclipse.xtext.formatting2.regionaccess.internal.NodeModelBasedRegionAccessBuilder.process(NodeModelBasedRegionAccessBuilder.java:214)
at org.eclipse.xtext.formatting2.regionaccess.internal.NodeModelBasedRegionAccessBuilder.getEObjectToTokensMap(NodeModelBasedRegionAccessBuilder.java:86)
at org.eclipse.xtext.formatting2.regionaccess.internal.NodeModelBasedRegionAccess.<init>(NodeModelBasedRegionAccess.java:29)
at org.eclipse.xtext.formatting2.regionaccess.internal.NodeModelBasedRegionAccessBuilder.create(NodeModelBasedRegionAccessBuilder.java:57)
at org.eclipse.xtext.formatting2.regionaccess.TextRegionAccessBuilder.create(TextRegionAccessBuilder.java:37)
at org.eclipse.xtext.ui.editor.formatting2.ContentFormatter.initRequest(ContentFormatter.java:126)
at org.eclipse.xtext.ui.editor.formatting2.ContentFormatter.exec(ContentFormatter.java:88)
堆栈跟踪中有更多条目。
陶氏有没有建议如何解决这个问题？