diff --git a/java_gen/java_type.py b/java_gen/java_type.py
index 471f1a8..1920bed 100644
--- a/java_gen/java_type.py
+++ b/java_gen/java_type.py
@@ -501,6 +501,8 @@
            )
 udf = JType("UDF") \
          .op(version=ANY, read="UDF.read4Bytes(bb)", write="$name.write4Bytes(bb)", default="UDF.ZERO")
+error_cause_data = JType("OFErrorCauseData") \
+         .op(version=ANY, read="OFErrorCauseData.read(bb, $length, OFVersion.OF_$version)", write="$name.writeTo(bb)");
 
 generic_t = JType("T")
 
@@ -716,6 +718,8 @@
     elif field_name == "err_type":
         return JType("OFErrorType", 'short') \
             .op(read='bb.readShort()', write='bb.writeShort($name)')
+    elif loxi_utils.class_is(obj_name, "of_error_msg") and field_name == "data":
+        return error_cause_data
     elif field_name == "stats_type":
         return JType("OFStatsType", 'short') \
             .op(read='bb.readShort()', write='bb.writeShort($name)')
diff --git a/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/OFErrorCauseData.java b/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/OFErrorCauseData.java
new file mode 100644
index 0000000..b5c7af0
--- /dev/null
+++ b/java_gen/pre-written/src/main/java/org/projectfloodlight/openflow/types/OFErrorCauseData.java
@@ -0,0 +1,121 @@
+package org.projectfloodlight.openflow.types;
+
+import java.util.Arrays;
+
+import org.jboss.netty.buffer.ChannelBuffer;
+import org.jboss.netty.buffer.ChannelBuffers;
+import org.projectfloodlight.openflow.exceptions.OFParseError;
+import org.projectfloodlight.openflow.protocol.OFErrorMsg;
+import org.projectfloodlight.openflow.protocol.OFFactories;
+import org.projectfloodlight.openflow.protocol.OFFactory;
+import org.projectfloodlight.openflow.protocol.OFMessage;
+import org.projectfloodlight.openflow.protocol.OFVersion;
+import org.projectfloodlight.openflow.protocol.Writeable;
+import org.projectfloodlight.openflow.util.ChannelUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.google.common.base.Optional;
+import com.google.common.hash.PrimitiveSink;
+
+/** A special-purpose wrapper for the 'data' field in an {@link OFErrorMsg} message
+ *  that contains a byte serialization of the offending message.
+ *
+ *  This attempts to parse the offending message on demand, and if successful
+ *  will present the parsed message.
+ *
+ * @author Andreas Wundsam <andreas.wundsam@bigswitch.com>
+ */
+public class OFErrorCauseData implements Writeable, PrimitiveSinkable {
+    private static final Logger logger =
+            LoggerFactory.getLogger(OFErrorCauseData.class);
+
+    private final byte[] data;
+    private final OFVersion version;
+
+    private OFErrorCauseData(byte[] data, OFVersion version) {
+        this.data = data;
+        this.version = version;
+    }
+
+    public static OFErrorCauseData of(byte[] data, OFVersion version) {
+         return new OFErrorCauseData(Arrays.copyOf(data, data.length), version);
+    }
+
+    public byte[] getData() {
+        return Arrays.copyOf(data, data.length);
+    }
+
+    public Optional<OFMessage> getParsedMessage() {
+        OFFactory factory = OFFactories.getFactory(version);
+        try {
+            OFMessage msg = factory.getReader().readFrom(ChannelBuffers.wrappedBuffer(data));
+            if(msg != null)
+                return Optional.of(msg);
+            else
+                return Optional.absent();
+        } catch (OFParseError e) {
+            logger.debug("Error parsing error cause data as OFMessage: {}", e.getMessage(), e);
+            return Optional.absent();
+        }
+    }
+
+    public static OFErrorCauseData read(ChannelBuffer bb, int length, OFVersion version) {
+        byte[] bytes = ChannelUtils.readBytes(bb, length);
+        return of(bytes, version);
+   }
+
+    @Override
+    public void putTo(PrimitiveSink sink) {
+        sink.putBytes(data);
+    }
+
+    @Override
+    public void writeTo(ChannelBuffer bb) {
+        bb.writeBytes(data);
+    }
+
+   @Override
+   public String toString() {
+      Optional<OFMessage> parsedMessage = getParsedMessage();
+      if(parsedMessage.isPresent()) {
+          return String.valueOf(parsedMessage.get());
+      } else {
+          StringBuilder b = new StringBuilder();
+          b.append("[unparsed: ");
+          for(int i=0; i<data.length; i++) {
+              if(i>0)
+                  b.append(" ");
+              b.append(String.format("%02x", data[i]));
+          }
+          b.append("]");
+          return b.toString();
+      }
+   }
+
+   @Override
+   public int hashCode() {
+       final int prime = 31;
+       int result = 1;
+       result = prime * result + Arrays.hashCode(data);
+       result = prime * result + ((version == null) ? 0 : version.hashCode());
+       return result;
+   }
+
+   @Override
+   public boolean equals(Object obj) {
+       if (this == obj)
+           return true;
+       if (obj == null)
+           return false;
+       if (getClass() != obj.getClass())
+           return false;
+       OFErrorCauseData other = (OFErrorCauseData) obj;
+       if (!Arrays.equals(data, other.data))
+           return false;
+       if (version != other.version)
+           return false;
+       return true;
+   }
+
+}
\ No newline at end of file
diff --git a/java_gen/pre-written/src/test/java/org/projectfloodlight/openflow/types/OFErrorCauseDataTest.java b/java_gen/pre-written/src/test/java/org/projectfloodlight/openflow/types/OFErrorCauseDataTest.java
new file mode 100644
index 0000000..9a5a4dc
--- /dev/null
+++ b/java_gen/pre-written/src/test/java/org/projectfloodlight/openflow/types/OFErrorCauseDataTest.java
@@ -0,0 +1,74 @@
+package org.projectfloodlight.openflow.types;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.junit.Assert.assertThat;
+
+import org.hamcrest.Matchers;
+import org.jboss.netty.buffer.ChannelBuffer;
+import org.jboss.netty.buffer.ChannelBuffers;
+import org.junit.Test;
+import org.projectfloodlight.openflow.protocol.OFFactories;
+import org.projectfloodlight.openflow.protocol.OFFlowAdd;
+import org.projectfloodlight.openflow.protocol.OFVersion;
+
+public class OFErrorCauseDataTest {
+    @Test
+    public void testEmpty() {
+        OFErrorCauseData emptyCause = OFErrorCauseData.of(new byte[] {}, OFVersion.OF_13);
+        assertThat(emptyCause.getData(), equalTo(new byte[] {}));
+        assertThat(emptyCause.getParsedMessage().isPresent(), equalTo(false));
+        assertThat(emptyCause.toString(), Matchers.containsString("unparsed"));
+    }
+
+    @Test
+    public void testTooShort() {
+        OFErrorCauseData emptyCause = OFErrorCauseData.of(new byte[] {0x1, 0x2}, OFVersion.OF_13);
+        assertThat(emptyCause.getData(), equalTo(new byte[] {0x1, 0x2}));
+        assertThat(emptyCause.getParsedMessage().isPresent(), equalTo(false));
+        assertThat(emptyCause.toString(), Matchers.containsString("unparsed"));
+        assertThat(emptyCause.toString(), Matchers.containsString("01 02"));
+    }
+
+    byte[] truncatedFlowAddd = new byte[] {
+            0x04, 0x0e, // version, type
+            0x00, (byte) 0x80, // length
+            0x12, 0x34, 0x56, 0x78, // xid
+            (byte) 0xfe, (byte) 0xdc , (byte) 0xba, (byte) 0x98, 0x76, 0x54, 0x32, 0x10, // cookie
+            (byte) 0xff, 0x00, (byte) 0xff, 0x00, (byte) 0xff, 0x00, (byte) 0xff, 0x00, // cookie_mask
+            0x03 // table_id
+            // rest truncated
+    };
+
+    @Test
+    public void testTruncated() {
+        OFErrorCauseData emptyCause = OFErrorCauseData.of(truncatedFlowAddd, OFVersion.OF_13);
+        assertThat(emptyCause.getData(), equalTo(truncatedFlowAddd));
+        assertThat(emptyCause.getParsedMessage().isPresent(), equalTo(false));
+        assertThat(emptyCause.toString(), Matchers.containsString("unparsed"));
+        assertThat(emptyCause.toString(), Matchers.containsString("04 0e 00 80"));
+    }
+
+    @Test
+    public void testFlowAdd() {
+        OFFlowAdd flowAdd = OFFactories.getFactory(OFVersion.OF_13).buildFlowAdd()
+        .setXid(0x12345678)
+        .setCookie(U64.parseHex("FEDCBA9876543210"))
+        .setCookieMask(U64.parseHex("FF00FF00FF00FF00"))
+        .setTableId(TableId.of(3))
+        .setIdleTimeout(5)
+        .setHardTimeout(10)
+        .setPriority(6000)
+        .build();
+
+        ChannelBuffer bb = ChannelBuffers.dynamicBuffer();
+        flowAdd.writeTo(bb);
+        byte[] flowAddBytes = new byte[bb.readableBytes()];
+        bb.readBytes(flowAddBytes);
+
+        OFErrorCauseData emptyCause = OFErrorCauseData.of(flowAddBytes, OFVersion.OF_13);
+        assertThat(emptyCause.getData(), equalTo(flowAddBytes));
+        assertThat(emptyCause.getParsedMessage().isPresent(), equalTo(true));
+        assertThat(emptyCause.toString(), Matchers.containsString("OFFlowAdd"));
+        assertThat(emptyCause.toString(), Matchers.containsString("idleTimeout=5"));
+    }
+}