diff --git a/.project b/.project
new file mode 100644
index 0000000..be389c2
--- /dev/null
+++ b/.project
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+        <name>FlowSpaceFirewall</name>
+        <comment></comment>
+        <projects>
+        </projects>
+        <buildSpec>
+                <buildCommand>
+                        <name>org.eclipse.jdt.core.javabuilder</name>
+                        <arguments>
+                        </arguments>
+                </buildCommand>
+        </buildSpec>
+        <natures>
+                <nature>org.eclipse.jdt.core.javanature</nature>
+        </natures>
+</projectDescription>
diff --git a/src/main/java/edu/iu/grnoc/flowspace_firewall/ConfigParser.java b/src/main/java/edu/iu/grnoc/flowspace_firewall/ConfigParser.java
index 9ecd726..f253e01 100644
--- a/src/main/java/edu/iu/grnoc/flowspace_firewall/ConfigParser.java
+++ b/src/main/java/edu/iu/grnoc/flowspace_firewall/ConfigParser.java
@@ -70,9 +70,10 @@ private static boolean isValidConfig(List<HashMap<Long, Slicer>> slices){
 					if(otherSlice.containsKey(dpid)){
 						Slicer otherConfig = otherSlice.get(dpid);
 						if(otherConfig.getSliceName() != config.getSliceName()){
-							if(config.hasOverlap(otherConfig)){
+							if(config.hasOverlap(otherConfig) != null){
 								log.warn("Overlap detected between slice "+config.getSliceName()+" and slice "
 								+otherConfig.getSliceName()+" will not load this configuration");
+								log.warn(config.hasOverlap(otherConfig)); //hasOverlap returns the details of the overlap.
 								return false;
 							}
 						}
@@ -199,8 +200,7 @@ public static ArrayList<HashMap<Long, Slicer>> parseConfig(String xmlFile) throw
 		        					}
 		        					if(tag_management && Short.parseShort(range.getAttributes().getNamedItem("start").getTextContent()) != Short.parseShort(range.getAttributes().getNamedItem("end").getTextContent())){
 		        						log.error("Tag Mangement can only be used on a single VLAN, please fix config and try again");
-		        						newSlices.clear();
-		        						return newSlices;
+		        						throw new InvalidConfigException("Configuration is not valid!");
 		        					}
 		        					for(short m = Short.parseShort(range.getAttributes().getNamedItem("start").getTextContent()); 
 		        							m <= Short.parseShort(range.getAttributes().getNamedItem("end").getTextContent()); m++){
@@ -213,8 +213,7 @@ public static ArrayList<HashMap<Long, Slicer>> parseConfig(String xmlFile) throw
 		        				slicer.setPortConfig(pConfig.getPortName(), pConfig);
 		        				if(tag_management == true && myRange.getAvailableTags().length > 1){
 		        					log.error("Tag Management can only be used on a single VLAN, please fix config and try again");
-		        					newSlices.clear();
-		        					return newSlices;
+		        					throw new InvalidConfigException("Configuration is not valid!");
 		        				}
 		        			}
 	        				//add the slicer to the whole slice container (all switches)
diff --git a/src/main/java/edu/iu/grnoc/flowspace_firewall/Slicer.java b/src/main/java/edu/iu/grnoc/flowspace_firewall/Slicer.java
index 46cd8c0..5a5b95e 100644
--- a/src/main/java/edu/iu/grnoc/flowspace_firewall/Slicer.java
+++ b/src/main/java/edu/iu/grnoc/flowspace_firewall/Slicer.java
@@ -43,7 +43,7 @@ public interface Slicer {
 	PortConfig getPortConfig(String portName);
 	PortConfig getPortConfig(short portId);
 	boolean isOkToProcessMessage();
-	boolean hasOverlap(Slicer otherSlicer);
+	String hasOverlap(Slicer otherSlicer);
 	String getSliceName();
 	void setSliceName(String name);
 	double getRate();
diff --git a/src/main/java/edu/iu/grnoc/flowspace_firewall/VLANSlicer.java b/src/main/java/edu/iu/grnoc/flowspace_firewall/VLANSlicer.java
index af87d39..87b2433 100644
--- a/src/main/java/edu/iu/grnoc/flowspace_firewall/VLANSlicer.java
+++ b/src/main/java/edu/iu/grnoc/flowspace_firewall/VLANSlicer.java
@@ -1106,16 +1106,17 @@ public void setSliceName(String name){
 		this.name = name;
 	}
 	
-	public boolean hasOverlap(Slicer otherSlicer){
+	public String hasOverlap(Slicer otherSlicer){
+		String error_detail = null;
 		for(String portName : this.portList.keySet()){
 			if(otherSlicer.isPortPartOfSlice(portName)){
 				if(this.getPortConfig(portName).getVlanRange().rangeOverlap(otherSlicer.getPortConfig(portName).getVlanRange())){
 					log.error(""+this.name+" "+this.getSliceName()+"port range: "+this.getPortConfig(portName).getVlanRange().toString()+ "overlaps with slice: "+otherSlicer.getSliceName()+" port-range: "+otherSlicer.getPortConfig(portName).getVlanRange().toString());
-					return true;
+					return ""+this.name+" "+this.getSliceName()+"port range: "+this.getPortConfig(portName).getVlanRange().toString()+ "overlaps with slice: "+otherSlicer.getSliceName()+" port-range: "+otherSlicer.getPortConfig(portName).getVlanRange().toString();
 				}
 			}
 		}
-		return false;
+		return error_detail;
 	}
 
 	public IOFSwitch getSwitch(){
diff --git a/src/test/java/edu/iu/grnoc/flowspace_firewall/VLANSlicerTest.java b/src/test/java/edu/iu/grnoc/flowspace_firewall/VLANSlicerTest.java
index deb0644..158b22c 100644
--- a/src/test/java/edu/iu/grnoc/flowspace_firewall/VLANSlicerTest.java
+++ b/src/test/java/edu/iu/grnoc/flowspace_firewall/VLANSlicerTest.java
@@ -602,7 +602,7 @@ public void testHasOverlap(){
 		pConfig6.setVLANRange(range);
 		otherSlicer.setPortConfig("foo6", pConfig6);
 		
-		assertFalse(slicer.hasOverlap(otherSlicer));
+		assertNull(slicer.hasOverlap(otherSlicer));
 		
 		pConfig = new PortConfig();
 		pConfig.setPortName("foo");
@@ -611,7 +611,7 @@ public void testHasOverlap(){
 		range.setVlanAvail((short)1000,true);
 		pConfig.setVLANRange(range);
 		otherSlicer.setPortConfig("foo", pConfig);
-		assertTrue(slicer.hasOverlap(otherSlicer));
+		assertNotNull(slicer.hasOverlap(otherSlicer));
 	}
 	
 	/*