diff --git a/app/__init__.py b/app/__init__.py
index a1862aaa70..66c6effd1c 100644
--- a/app/__init__.py
+++ b/app/__init__.py
@@ -205,6 +205,10 @@ def create_app(config_class=DevConfig):
     app = Flask(__name__, static_url_path="/ScoDoc/static", static_folder="static")
     app.wsgi_app = ReverseProxied(app.wsgi_app)
     app.logger.setLevel(logging.DEBUG)
+
+    # Evite de logguer toutes les requetes dans notre log
+    logging.getLogger("werkzeug").disabled = True
+
     app.config.from_object(config_class)
 
     db.init_app(app)
diff --git a/app/models/formations.py b/app/models/formations.py
index f35a48ce67..7db99a1fb5 100644
--- a/app/models/formations.py
+++ b/app/models/formations.py
@@ -14,6 +14,7 @@ from app.models.but_refcomp import (
     ApcParcoursNiveauCompetence,
 )
 from app.models.modules import Module
+from app.models.moduleimpls import ModuleImpl
 from app.models.ues import UniteEns
 from app.scodoc import sco_cache
 from app.scodoc import sco_codes_parcours
@@ -109,6 +110,13 @@ class Formation(db.Model):
         else:
             keys = f"{self.id}.{semestre_idx}"
         df_cache.ModuleCoefsCache.delete_many(keys | {f"{self.id}"})
+        # Invalidate aussi les poids de toutes les évals de la formation
+        for modimpl in ModuleImpl.query.filter(
+            ModuleImpl.module_id == Module.id,
+            Module.formation_id == self.id,
+        ):
+            modimpl.invalidate_evaluations_poids()
+
         sco_cache.invalidate_formsemestre()
 
     def invalidate_cached_sems(self):
diff --git a/app/scodoc/sco_bulletins.py b/app/scodoc/sco_bulletins.py
index df790649a6..daf4a9419d 100644
--- a/app/scodoc/sco_bulletins.py
+++ b/app/scodoc/sco_bulletins.py
@@ -158,9 +158,24 @@ def formsemestre_bulletinetud_dict(formsemestre_id, etudid, version="long"):
     I["server_name"] = request.url_root
 
     # Formation et parcours
-    I["formation"] = sco_formations.formation_list(
-        args={"formation_id": I["sem"]["formation_id"]}
-    )[0]
+    if I["sem"]["formation_id"]:
+        I["formation"] = sco_formations.formation_list(
+            args={"formation_id": I["sem"]["formation_id"]}
+        )[0]
+    else:  # what's the fuck ?
+        I["formation"] = {
+            "acronyme": "?",
+            "code_specialite": "",
+            "dept_id": 1,
+            "formation_code": "?",
+            "formation_id": -1,
+            "id": -1,
+            "referentiel_competence_id": None,
+            "titre": "?",
+            "titre_officiel": "?",
+            "type_parcours": 0,
+            "version": 0,
+        }
     I["parcours"] = sco_codes_parcours.get_parcours_from_code(
         I["formation"]["type_parcours"]
     )
diff --git a/app/scodoc/sco_cache.py b/app/scodoc/sco_cache.py
index 8fcc6f7efe..7975e3b2cf 100644
--- a/app/scodoc/sco_cache.py
+++ b/app/scodoc/sco_cache.py
@@ -67,6 +67,7 @@ class ScoDocCache:
 
     timeout = None  # ttl, infinite by default
     prefix = ""
+    verbose = False  # if true, verbose logging (debug)
 
     @classmethod
     def _get_key(cls, oid):
@@ -87,7 +88,10 @@ class ScoDocCache:
     def set(cls, oid, value):
         """Store value"""
         key = cls._get_key(oid)
-        # log(f"CACHE key={key}, type={type(value)}, timeout={cls.timeout}")
+        if cls.verbose:
+            log(
+                f"{cls.__name__}.set key={key}, type={type(value).__name__}, timeout={cls.timeout}"
+            )
         try:
             status = CACHE.set(key, value, timeout=cls.timeout)
             if not status:
@@ -101,11 +105,15 @@ class ScoDocCache:
     @classmethod
     def delete(cls, oid):
         """Remove from cache"""
+        # if cls.verbose:
+        #    log(f"{cls.__name__}.delete({oid})")
         CACHE.delete(cls._get_key(oid))
 
     @classmethod
     def delete_many(cls, oids):
         """Remove multiple keys at once"""
+        if cls.verbose:
+            log(f"{cls.__name__}.delete_many({oids})")
         # delete_many seems bugged:
         # CACHE.delete_many([cls._get_key(oid) for oid in oids])
         for oid in oids:
diff --git a/app/scodoc/sco_edit_ue.py b/app/scodoc/sco_edit_ue.py
index a2a6c05c8d..fd40ac2b85 100644
--- a/app/scodoc/sco_edit_ue.py
+++ b/app/scodoc/sco_edit_ue.py
@@ -122,12 +122,7 @@ def do_ue_create(args):
     # create
     ue_id = _ueEditor.create(cnx, args)
 
-    # Invalidate cache: vire les poids de toutes les évals de la formation
-    for modimpl in ModuleImpl.query.filter(
-        ModuleImpl.module_id == Module.id, Module.formation_id == args["formation_id"]
-    ):
-        modimpl.invalidate_evaluations_poids()
-    formation = Formation.query.get(args["formation_id"])
+    formation: Formation = Formation.query.get(args["formation_id"])
     formation.invalidate_module_coefs()
     # news
     ue = UniteEns.query.get(ue_id)
@@ -145,11 +140,10 @@ def do_ue_create(args):
 
 def do_ue_delete(ue_id, delete_validations=False, force=False):
     "delete UE and attached matieres (but not modules)"
-    from app.scodoc import sco_formations
     from app.scodoc import sco_parcours_dut
 
     ue = UniteEns.query.get_or_404(ue_id)
-    formation_id = ue.formation_id
+    formation = ue.formation
     semestre_idx = ue.semestre_idx
     if not ue.can_be_deleted():
         raise ScoNonEmptyFormationObject(
@@ -158,7 +152,7 @@ def do_ue_delete(ue_id, delete_validations=False, force=False):
             dest_url=url_for(
                 "notes.ue_table",
                 scodoc_dept=g.scodoc_dept,
-                formation_id=formation_id,
+                formation_id=formation.id,
                 semestre_idx=semestre_idx,
             ),
         )
@@ -182,7 +176,7 @@ def do_ue_delete(ue_id, delete_validations=False, force=False):
             cancel_url=url_for(
                 "notes.ue_table",
                 scodoc_dept=g.scodoc_dept,
-                formation_id=formation_id,
+                formation_id=formation.id,
                 semestre_idx=semestre_idx,
             ),
             parameters={"ue_id": ue.id, "dialog_confirmed": 1},
@@ -208,13 +202,13 @@ def do_ue_delete(ue_id, delete_validations=False, force=False):
     _ueEditor.delete(cnx, ue.id)
     # > UE delete + supr. validations associées etudiants (cas compliqué, mais rarement
     # utilisé: acceptable de tout invalider):
-    sco_cache.invalidate_formsemestre()
+    formation.invalidate_module_coefs()
+    # -> invalide aussi .invalidate_formsemestre()
     # news
-    F = sco_formations.formation_list(args={"formation_id": formation_id})[0]
     ScolarNews.add(
         typ=ScolarNews.NEWS_FORM,
-        obj=formation_id,
-        text=f"Modification de la formation {F['acronyme']}",
+        obj=formation.id,
+        text=f"Modification de la formation {formation.acronyme}",
         max_frequency=10 * 60,
     )
     #
@@ -223,7 +217,7 @@ def do_ue_delete(ue_id, delete_validations=False, force=False):
             url_for(
                 "notes.ue_table",
                 scodoc_dept=g.scodoc_dept,
-                formation_id=formation_id,
+                formation_id=formation.id,
                 semestre_idx=semestre_idx,
             )
         )
@@ -1317,8 +1311,9 @@ def do_ue_edit(args, bypass_lock=False, dont_invalidate_cache=False):
 
     formation = Formation.query.get(ue["formation_id"])
     if not dont_invalidate_cache:
-        # Invalide les semestres utilisant cette formation:
-        formation.invalidate_cached_sems()
+        # Invalide les semestres utilisant cette formation
+        # ainsi que les poids et coefs
+        formation.invalidate_module_coefs()
 
 
 # essai edition en ligne:
diff --git a/app/scodoc/sco_moduleimpl_status.py b/app/scodoc/sco_moduleimpl_status.py
index 1084314d6a..c49ef080a9 100644
--- a/app/scodoc/sco_moduleimpl_status.py
+++ b/app/scodoc/sco_moduleimpl_status.py
@@ -192,7 +192,7 @@ def moduleimpl_status(moduleimpl_id=None, partition_id=None):
     """Tableau de bord module (liste des evaluations etc)"""
     if not isinstance(moduleimpl_id, int):
         raise ScoInvalidIdType("moduleimpl_id must be an integer !")
-    modimpl = ModuleImpl.query.get_or_404(moduleimpl_id)
+    modimpl: ModuleImpl = ModuleImpl.query.get_or_404(moduleimpl_id)
     M = modimpl.to_dict()
     formsemestre_id = modimpl.formsemestre_id
     Mod = sco_edit_module.module_list(args={"module_id": modimpl.module_id})[0]