After upgrading Xtext in my Eclipse from 2.3.1 to 2.4.3, I see these errors in the log:
org.eclipse.xtext.parser.ParseException: java.lang.ClassCastException: org.eclipse.xtext.impl.KeywordImpl cannot be cast to org.eclipse.xtext.RuleCall
at org.eclipse.xtext.parser.antlr.AbstractAntlrParser.doParse(AbstractAntlrParser.java:105)
at org.eclipse.xtext.parser.antlr.AbstractAntlrParser.parse(AbstractAntlrParser.java:84)
at org.eclipse.xtext.parser.antlr.AbstractAntlrParser.doParse(AbstractAntlrParser.java:62)
at org.eclipse.xtext.parser.AbstractParser.parse(AbstractParser.java:32)
at org.eclipse.xtext.resource.XtextResource.doLoad(XtextResource.java:162)
at org.eclipse.xtext.linking.lazy.LazyLinkingResource.doLoad(LazyLinkingResource.java:81)
at org.eclipse.emf.ecore.resource.impl.ResourceImpl.load(ResourceImpl.java:1518)
at org.eclipse.xtext.ui.editor.model.XtextDocumentProvider.loadResource(XtextDocumentProvider.java:227)
What's causing this? How do I get rid of them?