diff --git a/app/comp/moy_sem.py b/app/comp/moy_sem.py
index 6a44dbc00..2aec3b736 100644
--- a/app/comp/moy_sem.py
+++ b/app/comp/moy_sem.py
@@ -30,8 +30,7 @@
 import numpy as np
 import pandas as pd
 
-from flask import g, url_for
-from app.scodoc.sco_exceptions import ScoValueError
+from flask import flash
 
 
 def compute_sem_moys_apc_using_coefs(
@@ -66,12 +65,8 @@ def compute_sem_moys_apc_using_ects(
         moy_gen = (etud_moy_ue_df * ects).sum(axis=1) / sum(ects)
     except TypeError:
         if None in ects:
-            raise ScoValueError(
-                f"""Calcul impossible: ECTS des UE manquants !
-            voir <a href="{url_for("notes.ue_table", scodoc_dept=g.scodoc_dept,
-             formation_id=formation_id)}">la page du programme</a>.
-            """
-            )
+            flash(f"""Calcul moyenne générale impossible: ECTS des UE manquants !""")
+            moy_gen = pd.Series(np.NaN, index=etud_moy_ue_df.index)
         else:
             raise
     return moy_gen
diff --git a/app/comp/res_common.py b/app/comp/res_common.py
index 7fa75c1b7..6a821ac69 100644
--- a/app/comp/res_common.py
+++ b/app/comp/res_common.py
@@ -259,9 +259,8 @@ class ResultatsSemestre(ResultatsCache):
         cur_moy_ue = self.etud_moy_ue[ue_id][etudid]
         moy_ue = cur_moy_ue
         is_capitalized = False  # si l'UE prise en compte est une UE capitalisée
-        was_capitalized = (
-            False  # s'il y a precedemment une UE capitalisée (pas forcement meilleure)
-        )
+        # s'il y a precedemment une UE capitalisée (pas forcement meilleure):
+        was_capitalized = False
         if etudid in self.validations.ue_capitalisees.index:
             ue_cap = self._get_etud_ue_cap(etudid, ue)
             if ue_cap and not np.isnan(ue_cap["moy_ue"]):
diff --git a/app/models/ues.py b/app/models/ues.py
index 09469fb05..2bed88a38 100644
--- a/app/models/ues.py
+++ b/app/models/ues.py
@@ -54,13 +54,15 @@ class UniteEns(db.Model):
             'EXTERNE' if self.is_external else ''})>"""
 
     def to_dict(self):
-        """as a dict, with the same conversions as in ScoDoc7"""
+        """as a dict, with the same conversions as in ScoDoc7
+        (except ECTS: keep None)
+        """
         e = dict(self.__dict__)
         e.pop("_sa_instance_state", None)
         # ScoDoc7 output_formators
         e["ue_id"] = self.id
         e["numero"] = e["numero"] if e["numero"] else 0
-        e["ects"] = e["ects"] if e["ects"] else 0.0
+        e["ects"] = e["ects"]
         e["coefficient"] = e["coefficient"] if e["coefficient"] else 0.0
         e["code_apogee"] = e["code_apogee"] or ""  # pas de None
         return e
diff --git a/app/scodoc/sco_edit_ue.py b/app/scodoc/sco_edit_ue.py
index 8f9488557..73e77dbbd 100644
--- a/app/scodoc/sco_edit_ue.py
+++ b/app/scodoc/sco_edit_ue.py
@@ -89,6 +89,7 @@ _ueEditor = ndb.EditableTable(
     input_formators={
         "type": ndb.int_null_is_zero,
         "is_external": ndb.bool_or_str,
+        "ects": ndb.float_null_is_null,
     },
     output_formators={
         "numero": ndb.int_null_is_zero,
@@ -347,6 +348,7 @@ def ue_edit(ue_id=None, create=False, formation_id=None, default_semestre_idx=No
                 "type": "float",
                 "title": "ECTS",
                 "explanation": "nombre de crédits ECTS",
+                "allow_null": not is_apc,  # ects requis en APC
             },
         ),
         (
@@ -933,10 +935,10 @@ def _ue_table_ues(
     cur_ue_semestre_id = None
     iue = 0
     for ue in ues:
-        if ue["ects"]:
-            ue["ects_str"] = ", %g ECTS" % ue["ects"]
-        else:
+        if ue["ects"] is None:
             ue["ects_str"] = ""
+        else:
+            ue["ects_str"] = ", %g ECTS" % ue["ects"]
         if editable:
             klass = "span_apo_edit"
         else:
@@ -1295,7 +1297,6 @@ def do_ue_edit(args, bypass_lock=False, dont_invalidate_cache=False):
                 f"""Acronyme d'UE "{args['acronyme']}" déjà utilisé ! 
                 (chaque UE doit avoir un acronyme unique dans la formation)"""
             )
-
     # On ne peut pas supprimer le code UE:
     if "ue_code" in args and not args["ue_code"]:
         del args["ue_code"]
diff --git a/app/static/css/scodoc.css b/app/static/css/scodoc.css
index bd99c80c6..3b80f7d6d 100644
--- a/app/static/css/scodoc.css
+++ b/app/static/css/scodoc.css
@@ -1671,7 +1671,10 @@ div.formation_list_modules ul.notes_module_list {
   padding-top: 5px;
   padding-bottom: 5px;
 }
-
+span.missing_ue_ects {
+  color: red;
+  font-weight: bold;
+}
 li.module_malus span.formation_module_tit {
   color: red;
   font-weight: bold;
diff --git a/app/templates/pn/form_ues.html b/app/templates/pn/form_ues.html
index 0cd3e333b..98c590f7b 100644
--- a/app/templates/pn/form_ues.html
+++ b/app/templates/pn/form_ues.html
@@ -38,7 +38,8 @@
                     {% set virg = joiner(", ") %}
                     <span class="ue_code">(
                         {%- if ue.ue_code -%}{{ virg() }}code {{ue.ue_code}} {%- endif -%} 
-                        {{ virg() }}{{ue.ects or 0}} ECTS)
+                        {{ virg() }}{{ue.ects if ue.ects is not none 
+                        else '<span class="missing_ue_ects">aucun</span>'|safe}} ECTS)
                     </span>
                 </span>