diff --git a/src/main/java/de/ids_mannheim/korap/query/serialize/CollectionQueryBuilder2.java b/src/main/java/de/ids_mannheim/korap/query/serialize/CollectionQueryBuilder2.java
index 7f68b64..5f37988 100644
--- a/src/main/java/de/ids_mannheim/korap/query/serialize/CollectionQueryBuilder2.java
+++ b/src/main/java/de/ids_mannheim/korap/query/serialize/CollectionQueryBuilder2.java
@@ -16,13 +16,20 @@
     private List<Map> rq;
     private Map groups;
     private CollectionTypes types;
+    private boolean verbose;
 
     public CollectionQueryBuilder2() {
+        this.verbose = false;
         this.rq = new ArrayList<>();
         this.groups = new HashMap();
         this.types = new CollectionTypes();
     }
 
+    public CollectionQueryBuilder2(boolean verbose) {
+        this();
+        this.verbose = verbose;
+    }
+
 
     public CollectionQueryBuilder2 addResource(String collections) {
         try {
@@ -43,8 +50,7 @@
     public CollectionQueryBuilder2 setQuery(String query) throws QueryException {
         CollectionQueryTree tree = new CollectionQueryTree();
         tree.process(query);
-        this.groups = (Map) tree.getRequestMap().get("query");
-        System.out.println("RAW QUERY: " + this.groups);
+        this.groups = tree.getRequestMap();
         return this;
     }
 
@@ -54,18 +60,22 @@
         return list;
     }
 
+    private Object raw2() {
+        return this.groups;
+    }
+
     public String toCollections() {
         Map value = new HashMap();
-        value.put("collections", raw());
+        value.put("collections", raw2());
         return JsonUtils.toJSON(value);
     }
 
     public JsonNode toNode() {
-        return JsonUtils.valueToTree(raw());
+        return JsonUtils.valueToTree(raw2());
     }
 
     public String toJSON() {
-        return JsonUtils.toJSON(raw());
+        return JsonUtils.toJSON(raw2());
     }
 
 
diff --git a/src/main/java/de/ids_mannheim/korap/query/serialize/QuerySerializer.java b/src/main/java/de/ids_mannheim/korap/query/serialize/QuerySerializer.java
index 75f9803..6e86dc4 100644
--- a/src/main/java/de/ids_mannheim/korap/query/serialize/QuerySerializer.java
+++ b/src/main/java/de/ids_mannheim/korap/query/serialize/QuerySerializer.java
@@ -4,6 +4,8 @@
 import com.fasterxml.jackson.databind.JsonMappingException;
 import de.ids_mannheim.korap.util.QueryException;
 import de.ids_mannheim.korap.utils.JsonUtils;
+import de.ids_mannheim.korap.utils.KorAPLogger;
+import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
@@ -14,6 +16,7 @@
  */
 public class QuerySerializer {
 
+    private Logger qllogger = KorAPLogger.initiate("ql");
     public static String queryLanguageVersion;
 
     private AbstractSyntaxTree ast;
@@ -95,6 +98,11 @@
 
     public QuerySerializer setQuery(String query, String ql, String version)
             throws QueryException {
+
+        if (query.isEmpty())
+            throw new QueryException(406, "No Content!");
+
+
         try {
             if (ql.equalsIgnoreCase("poliqarp")) {
                 ast = new PoliqarpPlusTree(query);
@@ -103,8 +111,10 @@
             } else if (ql.equalsIgnoreCase("poliqarpplus")) {
                 ast = new PoliqarpPlusTree(query);
             } else if (ql.equalsIgnoreCase("cql")) {
-//                queryLanguageVersion = "1.2"; // set me
-                ast = new CQLTree(query, version);
+                if (version == null)
+                    ast = new CQLTree(query);
+                else
+                    ast = new CQLTree(query, version);
             } else if (ql.equalsIgnoreCase("annis")) {
                 ast = new AqlTree(query);
             } else {
@@ -113,6 +123,7 @@
         } catch (QueryException e) {
             throw e;
         } catch (Exception e) {
+            e.printStackTrace();
             throw new QueryException("UNKNOWN: Query could not be parsed (" + query + ")");
         }
         return this;
@@ -123,7 +134,9 @@
     }
 
     public final String toJSON() {
-        return JsonUtils.toJSON(raw());
+        String ser = JsonUtils.toJSON(raw());
+        qllogger.info("Serialized query: " + ser);
+        return ser;
     }
 
     public final Map build() {
diff --git a/src/test/java/CollectionQueryTreeTest.java b/src/test/java/CollectionQueryTreeTest.java
index aef9d49..24aadfd 100644
--- a/src/test/java/CollectionQueryTreeTest.java
+++ b/src/test/java/CollectionQueryTreeTest.java
@@ -1,13 +1,9 @@
-import static org.junit.Assert.*;
-import de.ids_mannheim.korap.query.serialize.CollectionQueryBuilder;
-import de.ids_mannheim.korap.query.serialize.CollectionQueryBuilder2;
 import de.ids_mannheim.korap.query.serialize.CollectionQueryTree;
-import de.ids_mannheim.korap.resource.Relation;
 import de.ids_mannheim.korap.util.QueryException;
-import de.ids_mannheim.korap.utils.JsonUtils;
-import de.ids_mannheim.korap.utils.TimeUtils;
 import org.junit.Test;
 
+import static org.junit.Assert.assertEquals;
+
 public class CollectionQueryTreeTest {
 
 	CollectionQueryTree cqt;
@@ -166,8 +162,8 @@
 		cqt.process(query);
 		map = cqt.getRequestMap().toString();
 		assertEquals(expected.replaceAll(" ", ""), map.replaceAll(" ", ""));
-		
-		query = "(textClass=Sport & textClass=ausland) | (corpusID=WPD & author=White & year=2010)";
+
+        query = "(textClass=Sport & textClass=ausland) | (corpusID=WPD & author=White & year=2010)";
 		expected = 
 			"{@type=korap:filter, filter=" +
 				"{@type=korap:docGroup, relation=relation:or, operands=[" +