diff --git a/packages/CLPBN/horus/BayesBallGraph.cpp b/packages/CLPBN/horus/BayesBallGraph.cpp
index 3a6aa00bb..28e73b6bd 100644
--- a/packages/CLPBN/horus/BayesBallGraph.cpp
+++ b/packages/CLPBN/horus/BayesBallGraph.cpp
@@ -81,6 +81,7 @@ BayesBallGraph::exportToGraphViz (const char* fileName)
   std::ofstream out (fileName);
   if (!out.is_open()) {
     std::cerr << "Error: couldn't open file '" << fileName << "'." ;
+    std::cerr << std::endl;
     return;
   }
   out << "digraph {" << std::endl;
diff --git a/packages/CLPBN/horus/ConstraintTree.cpp b/packages/CLPBN/horus/ConstraintTree.cpp
index 1dc7f20c5..ac6f705e1 100644
--- a/packages/CLPBN/horus/ConstraintTree.cpp
+++ b/packages/CLPBN/horus/ConstraintTree.cpp
@@ -538,6 +538,7 @@ ConstraintTree::exportToGraphViz (
   std::ofstream out (fileName);
   if (!out.is_open()) {
     std::cerr << "Error: couldn't open file '" << fileName << "'." ;
+    std::cerr << std::endl;
     return;
   }
   out << "digraph {" << std::endl;
diff --git a/packages/CLPBN/horus/ElimGraph.cpp b/packages/CLPBN/horus/ElimGraph.cpp
index 82326beda..6e87eb78e 100644
--- a/packages/CLPBN/horus/ElimGraph.cpp
+++ b/packages/CLPBN/horus/ElimGraph.cpp
@@ -99,6 +99,7 @@ ElimGraph::exportToGraphViz (
   std::ofstream out (fileName);
   if (!out.is_open()) {
     std::cerr << "Error: couldn't open file '" << fileName << "'." ;
+    std::cerr << std::endl;
     return;
   }
   out << "strict graph {" << std::endl;
diff --git a/packages/CLPBN/horus/FactorGraph.cpp b/packages/CLPBN/horus/FactorGraph.cpp
index 704123194..312c53a92 100644
--- a/packages/CLPBN/horus/FactorGraph.cpp
+++ b/packages/CLPBN/horus/FactorGraph.cpp
@@ -54,6 +54,7 @@ FactorGraph::readFromUaiFormat (const char* fileName)
   std::ifstream is (fileName);
   if (!is.is_open()) {
     std::cerr << "Error: couldn't open file '" << fileName << "'." ;
+    std::cerr << std::endl;
     exit (EXIT_FAILURE);
   }
   ignoreLines (is);
@@ -139,6 +140,7 @@ FactorGraph::readFromLibDaiFormat (const char* fileName)
   std::ifstream is (fileName);
   if (!is.is_open()) {
     std::cerr << "Error: couldn't open file '" << fileName << "'." ;
+    std::cerr << std::endl;
     exit (EXIT_FAILURE);
   }
   ignoreLines (is);
@@ -300,6 +302,7 @@ FactorGraph::exportToLibDai (const char* fileName) const
   std::ofstream out (fileName);
   if (!out.is_open()) {
     std::cerr << "Error: couldn't open file '" << fileName << "'." ;
+    std::cerr << std::endl;
     return;
   }
   out << facNodes_.size() << std::endl << std::endl;
@@ -331,6 +334,7 @@ FactorGraph::exportToUai (const char* fileName) const
   std::ofstream out (fileName);
   if (!out.is_open()) {
     std::cerr << "Error: couldn't open file '" << fileName << "'." ;
+    std::cerr << std::endl;
     return;
   }
   out << (bayesFactors_ ? "BAYES" : "MARKOV") ;
@@ -377,6 +381,7 @@ FactorGraph::exportToGraphViz (const char* fileName) const
   std::ofstream out (fileName);
   if (!out.is_open()) {
     std::cerr << "Error: couldn't open file '" << fileName << "'." ;
+    std::cerr << std::endl;
     return;
   }
   out << "graph \"" << fileName << "\" {" << std::endl;
diff --git a/packages/CLPBN/horus/LiftedKc.cpp b/packages/CLPBN/horus/LiftedKc.cpp
index 4a1644ed4..e91bababe 100644
--- a/packages/CLPBN/horus/LiftedKc.cpp
+++ b/packages/CLPBN/horus/LiftedKc.cpp
@@ -285,6 +285,7 @@ LiftedCircuit::exportToGraphViz (const char* fileName)
   std::ofstream out (fileName);
   if (!out.is_open()) {
     std::cerr << "Error: couldn't open file '" << fileName << "'." ;
+    std::cerr << std::endl;
     return;
   }
   out << "digraph {" << std::endl;