This is an error that shows up in the error log when when opening a dsld file in my workspace. Here is the full stacktrace:

java.lang.NullPointerException
at org.eclipse.jdt.internal.compiler.lookup.TypeSystem.getParameterizedType(TypeSystem.java:300)
at org.eclipse.jdt.internal.compiler.lookup.TypeSystem.getParameterizedType(TypeSystem.java:304)
at org.eclipse.jdt.internal.compiler.lookup.LookupEnvironment.createParameterizedType(LookupEnvironment.java:1008)
at org.eclipse.jdt.internal.compiler.lookup.LookupEnvironment.getTypeFromTypeSignature(LookupEnvironment.java:1570)
at org.eclipse.jdt.internal.compiler.lookup.BinaryTypeBinding.createFields(BinaryTypeBinding.java:631)
at org.eclipse.jdt.internal.compiler.lookup.BinaryTypeBinding.cachePartsFrom(BinaryTypeBinding.java:528)
at org.eclipse.jdt.internal.compiler.lookup.LookupEnvironment.createBinaryTypeFrom(LookupEnvironment.java:732)
at org.eclipse.jdt.internal.compiler.lookup.LookupEnvironment.createBinaryTypeFrom(LookupEnvironment.java:715)
at org.eclipse.jdt.internal.compiler.Compiler.accept(Compiler.java:310)
at org.eclipse.jdt.internal.compiler.lookup.LookupEnvironment.askForType(LookupEnvironment.java:157)
at org.eclipse.jdt.internal.compiler.lookup.UnresolvedReferenceBinding.resolve(UnresolvedReferenceBinding.java:101)
at org.eclipse.jdt.internal.compiler.lookup.BinaryTypeBinding.resolveType(BinaryTypeBinding.java:217)
at org.eclipse.jdt.internal.compiler.lookup.PackageBinding.getTypeOrPackage(PackageBinding.java:186)
at org.eclipse.jdt.internal.compiler.lookup.Scope.getType(Scope.java:3035)
at org.codehaus.jdt.groovy.internal.compiler.ast.GroovyCompilationUnitScope.lookupClassNodeForSource(GroovyCompilationUnitScope.java:247)
at org.codehaus.jdt.groovy.internal.compiler.ast.JDTResolver.resolveFromCompileUnit(JDTResolver.java:184)
at org.codehaus.groovy.control.ResolveVisitor.resolve(ResolveVisitor.java:353)
at org.codehaus.jdt.groovy.internal.compiler.ast.JDTResolver.resolve(JDTResolver.java:365)
at org.codehaus.groovy.control.ResolveVisitor.resolve(ResolveVisitor.java:318)
at org.codehaus.jdt.groovy.internal.compiler.ast.JDTResolver.resolve(JDTResolver.java:375)
at org.codehaus.groovy.eclipse.dsl.lookup.ResolverCache.resolve(ResolverCache.java:76)
at org.codehaus.groovy.eclipse.dsl.contributions.PropertyContributionElement.ensureReturnType(PropertyContributionElement.java:93)
at org.codehaus.groovy.eclipse.dsl.contributions.PropertyContributionElement.lookupType(PropertyContributionElement.java:72)
at org.codehaus.groovy.eclipse.dsl.lookup.DSLDTypeLookup.lookupTypeAndDeclaration(DSLDTypeLookup.java:87)
at org.eclipse.jdt.groovy.search.AbstractSimplifiedTypeLookup.lookupType(AbstractSimplifiedTypeLookup.java:133)
at org.eclipse.jdt.groovy.search.TypeInferencingVisitorWithRequestor.lookupExpressionType(TypeInferencingVisitorWithRequestor.java:2266)
at org.eclipse.jdt.groovy.search.TypeInferencingVisitorWithRequestor.handleSimpleExpression(TypeInferencingVisitorWithRequestor.java:1835)
at org.eclipse.jdt.groovy.search.TypeInferencingVisitorWithRequestor.visitVariableExpression(TypeInferencingVisitorWithRequestor.java:1729)
at org.codehaus.groovy.ast.expr.VariableExpression.visit(VariableExpression.java:72)
at org.eclipse.jdt.groovy.search.TypeInferencingVisitorWithRequestor.visitMapEntryExpression(TypeInferencingVisitorWithRequestor.java:1325)
at org.codehaus.groovy.ast.expr.MapEntryExpression.visit(MapEntryExpression.java:39)
at org.eclipse.jdt.groovy.search.TypeInferencingVisitorWithRequestor.visitMapExpression(TypeInferencingVisitorWithRequestor.java:1388)
at org.codehaus.groovy.ast.expr.MapExpression.visit(MapExpression.java:55)
at org.codehaus.groovy.ast.CodeVisitorSupport.visitListOfExpressions(CodeVisitorSupport.java:278)
at org.codehaus.groovy.ast.CodeVisitorSupport.visitTupleExpression(CodeVisitorSupport.java:183)
at org.eclipse.jdt.groovy.search.TypeInferencingVisitorWithRequestor.visitTupleExpression(TypeInferencingVisitorWithRequestor.java:1680)
at org.codehaus.groovy.ast.expr.TupleExpression.visit(TupleExpression.java:78)
at org.eclipse.jdt.groovy.search.TypeInferencingVisitorWithRequestor.visitMethodCallExpression(TypeInferencingVisitorWithRequestor.java:1443)
at org.codehaus.groovy.ast.expr.MethodCallExpression.visit(MethodCallExpression.java:66)
at org.codehaus.groovy.ast.CodeVisitorSupport.visitExpressionStatement(CodeVisitorSupport.java:74)
at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitExpressionStatement(ClassCodeVisitorSupport.java:281)
at org.codehaus.groovy.ast.stmt.ExpressionStatement.visit(ExpressionStatement.java:42)
at org.codehaus.groovy.ast.CodeVisitorSupport.visitBlockStatement(CodeVisitorSupport.java:40)
at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitBlockStatement(ClassCodeVisitorSupport.java:251)
at org.eclipse.jdt.groovy.search.TypeInferencingVisitorWithRequestor.visitBlockStatement(TypeInferencingVisitorWithRequestor.java:939)
at org.codehaus.groovy.ast.stmt.BlockStatement.visit(BlockStatement.java:71)
at org.codehaus.groovy.ast.CodeVisitorSupport.visitClosureExpression(CodeVisitorSupport.java:179)
at org.eclipse.jdt.groovy.search.TypeInferencingVisitorWithRequestor.visitClosureExpression(TypeInferencingVisitorWithRequestor.java:1062)
at org.codehaus.groovy.ast.expr.ClosureExpression.visit(ClosureExpression.java:45)
at org.codehaus.groovy.ast.CodeVisitorSupport.visitListOfExpressions(CodeVisitorSupport.java:278)
at org.codehaus.groovy.ast.CodeVisitorSupport.visitTupleExpression(CodeVisitorSupport.java:183)
at org.eclipse.jdt.groovy.search.TypeInferencingVisitorWithRequestor.visitTupleExpression(TypeInferencingVisitorWithRequestor.java:1680)
at org.eclipse.jdt.groovy.search.TypeInferencingVisitorWithRequestor.visitArgumentlistExpression(TypeInferencingVisitorWithRequestor.java:814)
at org.codehaus.groovy.ast.expr.ArgumentListExpression.visit(ArgumentListExpression.java:76)
at org.eclipse.jdt.groovy.search.TypeInferencingVisitorWithRequestor.visitMethodCallExpression(TypeInferencingVisitorWithRequestor.java:1443)
at org.codehaus.groovy.ast.expr.MethodCallExpression.visit(MethodCallExpression.java:66)
at org.codehaus.groovy.ast.CodeVisitorSupport.visitExpressionStatement(CodeVisitorSupport.java:74)
at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitExpressionStatement(ClassCodeVisitorSupport.java:281)
at org.codehaus.groovy.ast.stmt.ExpressionStatement.visit(ExpressionStatement.java:42)
at org.codehaus.groovy.ast.CodeVisitorSupport.visitBlockStatement(CodeVisitorSupport.java:40)
at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitBlockStatement(ClassCodeVisitorSupport.java:251)
at org.eclipse.jdt.groovy.search.TypeInferencingVisitorWithRequestor.visitBlockStatement(TypeInferencingVisitorWithRequestor.java:939)
at org.codehaus.groovy.ast.stmt.BlockStatement.visit(BlockStatement.java:71)
at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitClassCodeContainer(ClassCodeVisitorSupport.java:148)
at org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitConstructorOrMethod(ClassCodeVisitorSupport.java:159)
at org.eclipse.jdt.groovy.search.TypeInferencingVisitorWithRequestor.visitConstructorOrMethod(TypeInferencingVisitorWithRequestor.java:1134)
at org.eclipse.jdt.groovy.search.TypeInferencingVisitorWithRequestor.visitJDT(TypeInferencingVisitorWithRequestor.java:521)
at org.eclipse.jdt.groovy.search.TypeInferencingVisitorWithRequestor.visitJDT(TypeInferencingVisitorWithRequestor.java:391)
at org.eclipse.jdt.groovy.search.TypeInferencingVisitorWithRequestor.visitCompilationUnit(TypeInferencingVisitorWithRequestor.java:350)
at org.codehaus.groovy.eclipse.editor.highlighting.GatherSemanticReferences.findSemanticHighlightingReferences(GatherSemanticReferences.java:46)
at org.codehaus.groovy.eclipse.editor.highlighting.GroovySemanticReconciler.reconciled(GroovySemanticReconciler.java:226)
at org.eclipse.jdt.internal.ui.javaeditor.CompilationUnitEditor.reconciled(CompilationUnitEditor.java:1687)
at org.eclipse.jdt.internal.ui.text.java.JavaReconcilingStrategy.reconciled(JavaReconcilingStrategy.java:219)
at org.eclipse.jdt.internal.ui.text.JavaCompositeReconcilingStrategy.reconciled(JavaCompositeReconcilingStrategy.java:164)
at org.eclipse.jdt.internal.ui.text.JavaCompositeReconcilingStrategy.initialReconcile(JavaCompositeReconcilingStrategy.java:144)
at org.eclipse.jface.text.reconciler.MonoReconciler.initialProcess(MonoReconciler.java:95)
at org.eclipse.jdt.internal.ui.text.JavaReconciler.initialProcess(JavaReconciler.java:420)
at org.eclipse.jface.text.reconciler.AbstractReconciler$BackgroundThread.run(AbstractReconciler.java:174)