Index: openacs-4/packages/xotcl-core/tcl/01-debug-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/xotcl-core/tcl/01-debug-procs.tcl,v
diff -u -r1.78.2.18 -r1.78.2.19
--- openacs-4/packages/xotcl-core/tcl/01-debug-procs.tcl	1 Oct 2016 12:17:00 -0000	1.78.2.18
+++ openacs-4/packages/xotcl-core/tcl/01-debug-procs.tcl	3 Oct 2016 12:07:32 -0000	1.78.2.19
@@ -165,8 +165,14 @@
   }
 }
 
-::xotcl::Object instproc serialize {} {
-  ::Serializer deepSerialize [self]
+if {[::package vcompare [package require xotcl::serializer] 2.0] < -1} {
+  #
+  # The serializer of xotcl/2.0 registers already a method "serialize"
+  # on Object. Don't mess with that.
+  #
+  ::xotcl::Object instproc serialize {} {
+    ::Serializer deepSerialize [self]
+  }
 }
 
 ::xotcl::Object instproc www-show-object {} {