diff --git a/src/main/java/org/gcube/dataanalysis/geo/algorithms/MapsComparator.java b/src/main/java/org/gcube/dataanalysis/geo/algorithms/MapsComparator.java
index 925f203..3a258e4 100644
--- a/src/main/java/org/gcube/dataanalysis/geo/algorithms/MapsComparator.java
+++ b/src/main/java/org/gcube/dataanalysis/geo/algorithms/MapsComparator.java
@@ -222,7 +222,9 @@ public class MapsComparator extends DataAnalysis {
 		GeoNetworkInspector fm = intersector.getFeaturer();
 		AnalysisLogger.getLogger().debug("MapsComparator: Taking info for the layer: " + layerID1);
 		Metadata meta1 = fm.getGNInfobyUUIDorName(layerID1);
-		if (meta1==null) throw new Exception("No Correspondence with Layer 1");
+		//patch to manage also external links
+		if (meta1==null) {return 0.5;}
+		//{throw new Exception("No Correspondence with Layer 1");}
 		double resolution1 = 0;
 		try {
 			resolution1 = GeoNetworkInspector.getResolution(meta1);
@@ -248,7 +250,7 @@ public class MapsComparator extends DataAnalysis {
 		AnalysisLogger.getLogger().debug("MapsComparator: Taking info for the layer: " + layerID2);
 		AnalysisLogger.getLogger().debug("MapsComparator: Trying with UUID..." + layerID2);
 		Metadata meta2 = fm.getGNInfobyUUIDorName(layerID2);
-		if (meta2==null) throw new Exception("No Correspondence with Layer 2");
+		if (meta2==null) {return 0.5;}//{throw new Exception("No Correspondence with Layer 2");}
 		
 		double resolution2 = 0;
 		try {