Index: openacs-4/packages/acs-templating/tcl/richtext-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-templating/tcl/richtext-procs.tcl,v
diff -u -r1.66 -r1.66.2.1
--- openacs-4/packages/acs-templating/tcl/richtext-procs.tcl	6 Dec 2018 21:24:17 -0000	1.66
+++ openacs-4/packages/acs-templating/tcl/richtext-procs.tcl	16 Oct 2019 09:54:06 -0000	1.66.2.1
@@ -76,7 +76,7 @@
     lassign $richtext_list contents format
 
     if { $contents ne "" && [lsearch -exact [template::util::richtext::formats] $format] == -1 } {
-        set message "Invalid format, '$format'."
+        set message "Invalid format, '[ns_quotehtml $format]'."
         return 0
     }