Index: openacs-4/packages/xowiki/tcl/xowiki-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/xowiki/tcl/xowiki-procs.tcl,v
diff -u -N -r1.542.2.172 -r1.542.2.173
--- openacs-4/packages/xowiki/tcl/xowiki-procs.tcl	22 Feb 2023 12:57:18 -0000	1.542.2.172
+++ openacs-4/packages/xowiki/tcl/xowiki-procs.tcl	22 Mar 2023 13:22:47 -0000	1.542.2.173
@@ -2245,7 +2245,7 @@
     renders it and returns either html or an error message.
   } {
     set page [:instantiate_includelet $arg]
-    if {$page eq ""} {
+    if {$page eq "" || ![nsf::is object $page]} {
       # The variable 'page_name' is required by the message key
       set page_name $arg
       return [:error_during_render [_ xowiki.error-includelet-unknown]]