diff --git a/phylogeny/distTree.cpp b/phylogeny/distTree.cpp
index d63799bd..1c0d2fb3 100644
--- a/phylogeny/distTree.cpp
+++ b/phylogeny/distTree.cpp
@@ -3142,7 +3142,8 @@ DistTree::DistTree (const string &treeFName,
   
   if (! getConnected ())
     throw runtime_error (FUNC "Disconnected objects");
-  setDiscernibles_ds ();  
+  if (! setDiscernibles_ds ())
+    return;
 
   if (isDirName (treeFName))
     setGlobalLen ();  // --> after dissim2Ds(), use dissims ??
@@ -3173,7 +3174,8 @@ DistTree::DistTree (const string &dissimFName,
         
   if (! getConnected ())
     throw runtime_error (FUNC "Disconnected objects");
-  setDiscernibles_ds ();
+  if (! setDiscernibles_ds ())
+    return;
 
   neighborJoin ();
   
@@ -3972,8 +3974,6 @@ DistTree::DistTree (Subgraph &subgraph,
   setPaths (false);
 
 
-//ASSERT (setDiscernibles_ds () == 0);
-
   qcPaths ();
 }
 
@@ -4511,7 +4511,7 @@ Cluster2Leaves DistTree::getIndiscernibles ()
 
 
 
-size_t DistTree::leafCluster2discernibles (const Cluster2Leaves &cluster2leaves)
+void DistTree::leafCluster2discernibles (const Cluster2Leaves &cluster2leaves)
 {
   ASSERT (! subDepth);
 
@@ -4574,13 +4574,11 @@ size_t DistTree::leafCluster2discernibles (const Cluster2Leaves &cluster2leaves)
   
   if (n)
     cleanTopology ();
-    
-  return n;
 }
 
 
 
-size_t DistTree::setDiscernibles_ds ()
+bool DistTree::setDiscernibles_ds ()
 {
   ASSERT (! subDepth);
   ASSERT (dissimDs. get ());
@@ -4599,9 +4597,6 @@ size_t DistTree::setDiscernibles_ds ()
     }
   }
   
-//if (DistTree_sp::variance_min)
-  //return 0;
-  
   FFOR (size_t, row, dissimDs->objs. size ())
     if (const Leaf* leaf1 = findPtr (name2leaf, dissimDs->objs [row] -> name))
       FOR (size_t, col, row)  // dissimAttr is symmetric
@@ -4616,16 +4611,16 @@ size_t DistTree::setDiscernibles_ds ()
     if (const Leaf* leaf = dtNode->asLeaf ())
       cluster2leaves [var_cast (leaf) -> getDisjointCluster ()] << leaf;
   }
+  ASSERT (! cluster2leaves. empty ());
   
-  if (cluster2leaves. size () == 1)
-    throw runtime_error (FUNC "No discernible objects");
- 
-  return leafCluster2discernibles (cluster2leaves);
+  leafCluster2discernibles (cluster2leaves);
+  
+  return cluster2leaves. size () > 1;
 }
 
 
 
-size_t DistTree::setDiscernibles ()
+void DistTree::setDiscernibles ()
 { 
   ASSERT (! subDepth);
   ASSERT (optimizable ());
@@ -4641,11 +4636,9 @@ size_t DistTree::setDiscernibles ()
   //return 0;
   
   const Cluster2Leaves cluster2leaves (getIndiscernibles ());
-  const size_t n = leafCluster2discernibles (cluster2leaves);
+  leafCluster2discernibles (cluster2leaves);
 
   qcPaths ();
-  
-  return n;
 }
 
 
diff --git a/phylogeny/distTree.hpp b/phylogeny/distTree.hpp
index 9818f4e0..8b173ad9 100644
--- a/phylogeny/distTree.hpp
+++ b/phylogeny/distTree.hpp
@@ -1262,12 +1262,13 @@ struct DistTree : Tree
     // Return: VectorPtr::size() >= 2
     // Invokes: Leaf->DisjointCluster
     // Time: ~ O(p)
-  size_t leafCluster2discernibles (const Cluster2Leaves &cluster2leaves);
+  void leafCluster2discernibles (const Cluster2Leaves &cluster2leaves);
     // Return: Number of indiscernible leaves
     // Output: Leaf::len = 0, Leaf::discernible = false, topology
     // Invokes: cleanTopology()
     // Time: O(n)
-  size_t setDiscernibles_ds ();
+  bool setDiscernibles_ds ();
+    // Return: success
     // Invokes: leafCluster2discernibles()
   void cleanTopology ();
     // Time: O(n)
@@ -1404,7 +1405,7 @@ struct DistTree : Tree
     // Time: O(p log(n) / threads_max)
   void qcPredictionAbsCriterion () const;
 public:
-  size_t setDiscernibles ();
+  void setDiscernibles ();
     // Invokes: getIndiscernibles(), leafCluster2discernibles()
   size_t fixTransients ();
     // Return: number of transient nodes deleted
diff --git a/phylogeny/makeDistTree.cpp b/phylogeny/makeDistTree.cpp
index 14186de1..17a893fc 100644
--- a/phylogeny/makeDistTree.cpp
+++ b/phylogeny/makeDistTree.cpp
@@ -401,6 +401,12 @@ struct ThisApplication : Application
                   );
     }
     ASSERT (tree. get ());
+    if (tree->getDiscernibles (). size () == 1)
+    {
+      cout << "One discernible object" << endl;
+      return;
+    }
+    
     ASSERT (optimizable == tree->optimizable ());
     
     if (variance_dissim)
diff --git a/version.inc b/version.inc
index 7acaf8b3..96108374 100644
--- a/version.inc
+++ b/version.inc
@@ -1,6 +1,7 @@
-#define VERSION "1.9.6"
+#define VERSION "1.9.7"
 
 
+// 1.9.7  07/06/2022  there may be 1 indiscernible object
 // 1.9.6  10/18/2021  distTree_inc_refresh_dissim.sh
 // 1.9.5  07/23/2021  -prefer_gain is restored in tree2names.sh
 // 1.9.4  06/09/2021  combine_dissims.cpp: -barrier