diff --git a/crlcore/etc/scmos_deep_018/alliance.conf b/crlcore/etc/scmos_deep_018/alliance.conf
index c8076079..32c1b9a8 100644
--- a/crlcore/etc/scmos_deep_018/alliance.conf
+++ b/crlcore/etc/scmos_deep_018/alliance.conf
@@ -11,7 +11,7 @@ cellsTop       = allianceTop+'/cells'
 allianceConfig = \
     ( ( 'CATALOG'            , 'CATAL')
     , ( 'WORKING_LIBRARY'    , '.')
-    , ( 'SYSTEM_LIBRARY'     , ( (cellsTop+'/msxlib'  , Environment.Append)
+    , ( 'SYSTEM_LIBRARY'     , ( (cellsTop+'/nsxlib'  , Environment.Append)
                                , (cellsTop+'/mpxlib'  , Environment.Append)) )
     , ( 'SCALE_X'            , 100)
     , ( 'IN_LO'              , 'vst')
diff --git a/crlcore/etc/scmos_deep_018/plugins.conf b/crlcore/etc/scmos_deep_018/plugins.conf
index 5b16ad52..a704c0ed 100644
--- a/crlcore/etc/scmos_deep_018/plugins.conf
+++ b/crlcore/etc/scmos_deep_018/plugins.conf
@@ -22,6 +22,6 @@ parametersTable = \
     , ('chip.pad.pvddeck'                 , TypeString, 'pvddeck_mpx')
     , ('chip.pad.pvsseck'                 , TypeString, 'pvsseck_mpx')
     , ('clockTree.minimumSide'            , TypeInt   , 1000)
-    , ('clockTree.buffer'                 , TypeString, 'bf1_x4')
+    , ('clockTree.buffer'                 , TypeString, 'buf_x2')
     , ('clockTree.placerEngine'           , TypeString, 'Etesian')
     )
diff --git a/cumulus/src/plugins/ChipPlugin.py b/cumulus/src/plugins/ChipPlugin.py
index 588f7eca..a8812e5e 100644
--- a/cumulus/src/plugins/ChipPlugin.py
+++ b/cumulus/src/plugins/ChipPlugin.py
@@ -219,7 +219,8 @@ def ScriptMain ( **kw ):
 
   except ErrorMessage, e:
     print e; errorCode = e.code
-    if editor: editor.fit()
+    if     locals().has_key('editor') and editor \
+       and locals().has_key('cell'  ) and cell: editor.fit()
     rvalue = False
   except Exception, e:
     print '\n\n', e; errorCode = 1
diff --git a/cumulus/src/plugins/clocktree/ClockTree.py b/cumulus/src/plugins/clocktree/ClockTree.py
index 6f52456f..584cecfc 100755
--- a/cumulus/src/plugins/clocktree/ClockTree.py
+++ b/cumulus/src/plugins/clocktree/ClockTree.py
@@ -132,6 +132,11 @@ class HTree ( GaugeConfWrapper ):
   def _getBufferIo ( self ):
     self.bufferCell = self.framework.getCell( Cfg.getParamString('clockTree.buffer').asString()
                                             , CRL.Catalog.State.Views )
+    if not self.bufferCell:
+      raise ErrorMessage( 3, [ 'ClockTree: Buffer cell "%s" not found in library,' \
+                               % Cfg.getParamString('clockTree.buffer').asString()
+                             , '           please check the "clockTree.buffer" configuration parameter in "plugins.conf".' ] )
+
     for net in self.bufferCell.getNets():
       if not net.isExternal(): continue
       if     net.isGlobal(): continue