diff --git a/data/maker/__init__.py b/data/maker/__init__.py
index 5053e9b..09bdb4c 100644
--- a/data/maker/__init__.py
+++ b/data/maker/__init__.py
@@ -501,7 +501,10 @@ class Generator (Learner):
         N = 0
         for _iodf in _candidates :
             _df = self._df.copy()
-            _df[self.columns] = _iodf[self.columns]
+            if self.columns :
+                _df[self.columns] = _iodf[self.columns]
+            
+                
             N += _df.shape[0]
             if self._states and 'post' in self._states:
                 _df = State.apply(_df,self._states['post'])
diff --git a/setup.py b/setup.py
index 7efb8c5..505dae7 100644
--- a/setup.py
+++ b/setup.py
@@ -4,7 +4,7 @@ import sys
 
 def read(fname):
     return open(os.path.join(os.path.dirname(__file__), fname)).read() 
-args = {"name":"data-maker","version":"1.6.6",
+args = {"name":"data-maker","version":"1.6.8",
         "author":"Vanderbilt University Medical Center","author_email":"steve.l.nyemba@vumc.org","license":"MIT",
         "packages":find_packages(),"keywords":["healthcare","data","transport","protocol"]}
 args["install_requires"] = ['data-transport@git+https://github.com/lnyemba/data-transport.git','tensorflow']