Index: library/nx/nx.tcl
===================================================================
diff -u -r2f6bcca3537584c8ef1f9fc71b230e79d1560504 -r7c704ea539925a2c4a2c8893b46b54a4f48dc5d8
--- library/nx/nx.tcl	(.../nx.tcl)	(revision 2f6bcca3537584c8ef1f9fc71b230e79d1560504)
+++ library/nx/nx.tcl	(.../nx.tcl)	(revision 7c704ea539925a2c4a2c8893b46b54a4f48dc5d8)
@@ -1804,7 +1804,7 @@
   }
 
   ::nx::VariableSlot protected method checkDefault {} {
-    if {![info exists :default]} {return}
+    if {![info exists :default] || [string match {*\[*\]*} ${:default}]} {return}
     set options [:getParameterOptions -withMultiplicity true]
     if {[llength $options] > 0} {
       if {[catch {::nsf::is -complain -configure -name ${:name}: [join $options ,] ${:default}} errorMsg]} {