diff --git a/org.eclipse.xtext/src/org/eclipse/xtext/generator/JavaIoFileSystemAccess.java b/org.eclipse.xtext/src/org/eclipse/xtext/generator/JavaIoFileSystemAccess.java
index 871a23d24..aec9e4944 100644
--- a/org.eclipse.xtext/src/org/eclipse/xtext/generator/JavaIoFileSystemAccess.java
+++ b/org.eclipse.xtext/src/org/eclipse/xtext/generator/JavaIoFileSystemAccess.java
@@ -23,6 +23,7 @@ import org.eclipse.emf.common.util.URI;
 import org.eclipse.xtext.generator.trace.AbstractTraceRegion;
 import org.eclipse.xtext.generator.trace.ITraceRegionProvider;
 import org.eclipse.xtext.generator.trace.TraceFileNameProvider;
+import org.eclipse.xtext.generator.trace.TraceNotFoundException;
 import org.eclipse.xtext.generator.trace.TraceRegionSerializer;
 import org.eclipse.xtext.parser.IEncodingProvider;
 import org.eclipse.xtext.resource.IResourceServiceProvider;
@@ -121,16 +122,21 @@ public class JavaIoFileSystemAccess extends AbstractFileSystemAccess2 {
 	protected void generateTrace(String generatedFile, String outputConfigName, CharSequence contents) {
 		try {
 			if (contents instanceof ITraceRegionProvider) {
-				String traceFileName = traceFileNameProvider.getTraceFromJava(generatedFile);
-				File traceFile = getFile(traceFileName, outputConfigName);
-				OutputStream out = new BufferedOutputStream(new FileOutputStream(traceFile));
+				OutputStream out = null;
 				try {
 					AbstractTraceRegion traceRegion = ((ITraceRegionProvider) contents).getTraceRegion();
+					String traceFileName = traceFileNameProvider.getTraceFromJava(generatedFile);
+					File traceFile = getFile(traceFileName, outputConfigName);
+					out = new BufferedOutputStream(new FileOutputStream(traceFile));
 					traceSerializer.writeTraceRegionTo(traceRegion, out);
 					if(callBack != null) 
 						callBack.fileAdded(traceFile);
-				} finally {
-					out.close();
+				} catch (TraceNotFoundException e) {
+					// ok
+				}finally {
+					if (out != null) {
+						out.close();
+					}
 				}
 			}
 		} catch (FileNotFoundException e) {
diff --git a/org.eclipse.xtext/src/org/eclipse/xtext/generator/URIBasedFileSystemAccess.xtend b/org.eclipse.xtext/src/org/eclipse/xtext/generator/URIBasedFileSystemAccess.xtend
index 1ad075fd4..e8b0d6466 100644
--- a/org.eclipse.xtext/src/org/eclipse/xtext/generator/URIBasedFileSystemAccess.xtend
+++ b/org.eclipse.xtext/src/org/eclipse/xtext/generator/URIBasedFileSystemAccess.xtend
@@ -10,6 +10,9 @@ package org.eclipse.xtext.generator
 import com.google.common.io.ByteStreams
 import com.google.common.io.CharStreams
 import java.io.ByteArrayInputStream
+import java.io.ByteArrayOutputStream
+import java.io.File
+import java.io.FileNotFoundException
 import java.io.InputStream
 import java.io.InputStreamReader
 import org.eclipse.emf.common.util.URI
@@ -21,9 +24,7 @@ import org.eclipse.xtext.generator.trace.TraceFileNameProvider
 import org.eclipse.xtext.generator.trace.TraceRegionSerializer
 import org.eclipse.xtext.parser.IEncodingProvider
 import org.eclipse.xtext.util.RuntimeIOException
-import java.io.ByteArrayOutputStream
-import java.io.File
-import java.io.FileNotFoundException
+import org.eclipse.xtext.generator.trace.TraceNotFoundException
 
 /**
  * A file system access implementation that is based on EMF URIs and URIConverter
@@ -91,11 +92,15 @@ class URIBasedFileSystemAccess extends AbstractFileSystemAccess2 {
 	
 	protected def void generateTrace(String generatedFile, String outputConfigName, CharSequence contents) {
 		if (isGenerateTraces && contents instanceof ITraceRegionProvider) {
-			var String traceFileName = traceFileNameProvider.getTraceFromJava(generatedFile)
-			val out = new ByteArrayOutputStream()
-			var AbstractTraceRegion traceRegion = (contents as ITraceRegionProvider).getTraceRegion()
-			traceRegionSerializer.writeTraceRegionTo(traceRegion, out)
-			generateFile(traceFileName, outputConfigName, new ByteArrayInputStream(out.toByteArray))
+			try {
+				var AbstractTraceRegion traceRegion = (contents as ITraceRegionProvider).getTraceRegion()
+				var String traceFileName = traceFileNameProvider.getTraceFromJava(generatedFile)
+				val out = new ByteArrayOutputStream()
+				traceRegionSerializer.writeTraceRegionTo(traceRegion, out)
+				generateFile(traceFileName, outputConfigName, new ByteArrayInputStream(out.toByteArray))
+			} catch (TraceNotFoundException e) {
+				// ok
+			}
 		}
 	}
 	
diff --git a/org.eclipse.xtext/src/org/eclipse/xtext/generator/trace/internal/AbstractTraceForURIProvider.java b/org.eclipse.xtext/src/org/eclipse/xtext/generator/trace/internal/AbstractTraceForURIProvider.java
index 54123d27a..68fda3603 100644
--- a/org.eclipse.xtext/src/org/eclipse/xtext/generator/trace/internal/AbstractTraceForURIProvider.java
+++ b/org.eclipse.xtext/src/org/eclipse/xtext/generator/trace/internal/AbstractTraceForURIProvider.java
@@ -205,7 +205,11 @@ public abstract class AbstractTraceForURIProvider<SomeFile, Trace extends Abstra
 			
 			@Override
 			public AbstractTraceRegion getTraceRegion() {
-				return cachedTraces.getTraceRegion(persistedTrace);
+				AbstractTraceRegion traceRegion = cachedTraces.getTraceRegion(persistedTrace);
+				if (traceRegion == null) {
+					throw new TraceNotFoundException();
+				}
+				return traceRegion;
 			}
 		});
 		return result;
diff --git a/org.eclipse.xtext/src/org/eclipse/xtext/generator/trace/node/GeneratorNodeProcessor.xtend b/org.eclipse.xtext/src/org/eclipse/xtext/generator/trace/node/GeneratorNodeProcessor.xtend
index 8869810ed..cbc97aa65 100644
--- a/org.eclipse.xtext/src/org/eclipse/xtext/generator/trace/node/GeneratorNodeProcessor.xtend
+++ b/org.eclipse.xtext/src/org/eclipse/xtext/generator/trace/node/GeneratorNodeProcessor.xtend
@@ -31,6 +31,9 @@ class GeneratorNodeProcessor {
 		AbstractTraceRegion traceRegion
 		
 		override getTraceRegion() throws TraceNotFoundException {
+			if (traceRegion === null) {
+				throw new TraceNotFoundException()
+			}
 			return traceRegion
 		}
 		
diff --git a/org.eclipse.xtext/xtend-gen/org/eclipse/xtext/generator/URIBasedFileSystemAccess.java b/org.eclipse.xtext/xtend-gen/org/eclipse/xtext/generator/URIBasedFileSystemAccess.java
index 08bcdb8db..3a05c097d 100644
--- a/org.eclipse.xtext/xtend-gen/org/eclipse/xtext/generator/URIBasedFileSystemAccess.java
+++ b/org.eclipse.xtext/xtend-gen/org/eclipse/xtext/generator/URIBasedFileSystemAccess.java
@@ -24,6 +24,7 @@ import org.eclipse.xtext.generator.IFilePostProcessor;
 import org.eclipse.xtext.generator.trace.AbstractTraceRegion;
 import org.eclipse.xtext.generator.trace.ITraceRegionProvider;
 import org.eclipse.xtext.generator.trace.TraceFileNameProvider;
+import org.eclipse.xtext.generator.trace.TraceNotFoundException;
 import org.eclipse.xtext.generator.trace.TraceRegionSerializer;
 import org.eclipse.xtext.parser.IEncodingProvider;
 import org.eclipse.xtext.util.RuntimeIOException;
@@ -130,13 +131,21 @@ public class URIBasedFileSystemAccess extends AbstractFileSystemAccess2 {
   protected void generateTrace(final String generatedFile, final String outputConfigName, final CharSequence contents) {
     try {
       if ((this.isGenerateTraces() && (contents instanceof ITraceRegionProvider))) {
-        String traceFileName = this.traceFileNameProvider.getTraceFromJava(generatedFile);
-        final ByteArrayOutputStream out = new ByteArrayOutputStream();
-        AbstractTraceRegion traceRegion = ((ITraceRegionProvider) contents).getTraceRegion();
-        this.traceRegionSerializer.writeTraceRegionTo(traceRegion, out);
-        byte[] _byteArray = out.toByteArray();
-        ByteArrayInputStream _byteArrayInputStream = new ByteArrayInputStream(_byteArray);
-        this.generateFile(traceFileName, outputConfigName, _byteArrayInputStream);
+        try {
+          AbstractTraceRegion traceRegion = ((ITraceRegionProvider) contents).getTraceRegion();
+          String traceFileName = this.traceFileNameProvider.getTraceFromJava(generatedFile);
+          final ByteArrayOutputStream out = new ByteArrayOutputStream();
+          this.traceRegionSerializer.writeTraceRegionTo(traceRegion, out);
+          byte[] _byteArray = out.toByteArray();
+          ByteArrayInputStream _byteArrayInputStream = new ByteArrayInputStream(_byteArray);
+          this.generateFile(traceFileName, outputConfigName, _byteArrayInputStream);
+        } catch (final Throwable _t) {
+          if (_t instanceof TraceNotFoundException) {
+            final TraceNotFoundException e = (TraceNotFoundException)_t;
+          } else {
+            throw Exceptions.sneakyThrow(_t);
+          }
+        }
       }
     } catch (Throwable _e) {
       throw Exceptions.sneakyThrow(_e);
diff --git a/org.eclipse.xtext/xtend-gen/org/eclipse/xtext/generator/trace/node/GeneratorNodeProcessor.java b/org.eclipse.xtext/xtend-gen/org/eclipse/xtext/generator/trace/node/GeneratorNodeProcessor.java
index a5a174829..8a07142f6 100644
--- a/org.eclipse.xtext/xtend-gen/org/eclipse/xtext/generator/trace/node/GeneratorNodeProcessor.java
+++ b/org.eclipse.xtext/xtend-gen/org/eclipse/xtext/generator/trace/node/GeneratorNodeProcessor.java
@@ -51,6 +51,9 @@ public class GeneratorNodeProcessor {
     
     @Override
     public AbstractTraceRegion getTraceRegion() throws TraceNotFoundException {
+      if ((this.traceRegion == null)) {
+        throw new TraceNotFoundException();
+      }
       return this.traceRegion;
     }