Index: openacs-4/packages/acs-templating/tcl/widget-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-templating/tcl/widget-procs.tcl,v
diff -u -r1.63.2.17 -r1.63.2.18
--- openacs-4/packages/acs-templating/tcl/widget-procs.tcl	24 Jan 2022 16:35:47 -0000	1.63.2.17
+++ openacs-4/packages/acs-templating/tcl/widget-procs.tcl	29 Mar 2022 11:01:47 -0000	1.63.2.18
@@ -677,7 +677,9 @@
     upvar $attribute_reference attributes
 
     # Create an array for easier testing of selected values
-    template::util::list_to_lookup $values_list values
+    if {[string is list $values_list]} {
+        template::util::list_to_lookup $values_list values
+    }
 
     set output {}
     if { $mode ne "edit" } {