diff --git a/src/main/java/de/dhbwstuttgart/typeinference/unify/TypeUnifyTask.java b/src/main/java/de/dhbwstuttgart/typeinference/unify/TypeUnifyTask.java
index 2778fd191..d2c1fc6b2 100644
--- a/src/main/java/de/dhbwstuttgart/typeinference/unify/TypeUnifyTask.java
+++ b/src/main/java/de/dhbwstuttgart/typeinference/unify/TypeUnifyTask.java
@@ -56,6 +56,7 @@ import java.io.OutputStreamWriter;
 import java.io.Writer;
 
 import com.google.common.collect.Ordering;
+import org.apache.commons.io.output.NullWriter;
 
 
 /**
@@ -161,7 +162,10 @@ public class TypeUnifyTask extends RecursiveTask<Set<Set<UnifyPair>>>  {
 		this.statistics = statistics;
 	}
 	public TypeUnifyTask(Set<UnifyPair> eq, List<Set<Constraint<UnifyPair>>> oderConstraints, IFiniteClosure fc, boolean parallel, Writer logFile, Boolean log, int rekTiefe, UnifyResultModel urm, UnifyTaskModel usedTasks) {
-		synchronized (this) { 
+		synchronized (this) {
+            if(statistics==null){
+                statistics = new NullWriter();
+            }
 			this.eq = eq;
 			//this.oderConstraints = oderConstraints.stream().map(x -> x.stream().map(y -> new HashSet<>(y)).collect(Collectors.toSet(HashSet::new))).collect(Collectors.toList(ArrayList::new));
 			this.oderConstraintsField = oderConstraints; /*.stream().map(x -> {