diff --git a/app/but/cursus_but.py b/app/but/cursus_but.py
index 9ae1671a..7f5c00b8 100644
--- a/app/but/cursus_but.py
+++ b/app/but/cursus_but.py
@@ -92,8 +92,11 @@ class EtudCursusBUT:
             [
                 ins
                 for ins in etud.formsemestre_inscriptions
-                if ins.formsemestre.formation.referentiel_competence.id
-                == formation.referentiel_competence.id
+                if ins.formsemestre.formation.referentiel_competence
+                and (
+                    ins.formsemestre.formation.referentiel_competence.id
+                    == formation.referentiel_competence.id
+                )
             ],
             key=lambda s: (s.formsemestre.semestre_id, s.formsemestre.date_debut),
         )
diff --git a/sco_version.py b/sco_version.py
index 89e2cd42..f62df4c9 100644
--- a/sco_version.py
+++ b/sco_version.py
@@ -1,7 +1,7 @@
 # -*- mode: python -*-
 # -*- coding: utf-8 -*-
 
-SCOVERSION = "9.4.27"
+SCOVERSION = "9.4.28"
 
 SCONAME = "ScoDoc"