Index: openacs-4/packages/assessment/tcl/as-install-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/assessment/tcl/as-install-procs.tcl,v
diff -u -N -r1.49.2.2 -r1.49.2.3
--- openacs-4/packages/assessment/tcl/as-install-procs.tcl	5 Mar 2020 15:44:22 -0000	1.49.2.2
+++ openacs-4/packages/assessment/tcl/as-install-procs.tcl	5 Mar 2020 16:05:05 -0000	1.49.2.3
@@ -1509,9 +1509,11 @@
                             -column_spec {char(1) default 'f'}
             }
             2.10.0d5 2.10.0d6 {
-                content::type::attribute::delete \
-                    -content_type {as_assessments} \
-                    -attribute_name {survey_p}
+                if { [attribute::exists_p as_assessments survey_p] } {
+                    content::type::attribute::delete \
+                        -content_type {as_assessments} \
+                        -attribute_name {survey_p}
+                }
             }
     }
 }