diff --git a/apps/participation/forms.py b/apps/participation/forms.py
index f80fefe..de77aba 100644
--- a/apps/participation/forms.py
+++ b/apps/participation/forms.py
@@ -61,7 +61,7 @@ class ParticipationForm(forms.ModelForm):
 
 class MotivationLetterForm(forms.ModelForm):
     def clean_file(self):
-        if "file" in self.files:
+        if "motivation_letter" in self.files:
             file = self.files["motivation_letter"]
             if file.size > 2e6:
                 raise ValidationError(_("The uploaded file size must be under 2 Mo."))
diff --git a/apps/participation/management/commands/fix_matrix_channels.py b/apps/participation/management/commands/fix_matrix_channels.py
index 4be6bb6..9213e9f 100644
--- a/apps/participation/management/commands/fix_matrix_channels.py
+++ b/apps/participation/management/commands/fix_matrix_channels.py
@@ -23,7 +23,10 @@ class Command(BaseCommand):
         else:  # pragma: no cover
             if not os.path.isfile(".matrix_avatar"):
                 avatar_uri = Matrix.get_avatar()
-                if not isinstance(avatar_uri, str):
+                if isinstance(avatar_uri, str):
+                    with open(".matrix_avatar", "w") as f:
+                        f.write(avatar_uri)
+                else:
                     stat_file = os.stat("tfjm/static/logo.png")
                     with open("tfjm/static/logo.png", "rb") as f:
                         resp = Matrix.upload(f, filename="logo.png", content_type="image/png",
diff --git a/apps/participation/views.py b/apps/participation/views.py
index afafbc7..235441f 100644
--- a/apps/participation/views.py
+++ b/apps/participation/views.py
@@ -391,7 +391,7 @@ class TeamAuthorizationsView(LoginRequiredMixin, DetailView):
                          _("Parental authorization of {participant}.{ext}")
                          .format(participant=str(participant), ext=ext))
 
-            if participant.health_sheet:
+            if isinstance(participant, StudentRegistration) and participant.health_sheet:
                 mime_type = magic.from_file("media/" + participant.health_sheet.name)
                 ext = mime_type.split("/")[1].replace("jpeg", "jpg")
                 zf.write("media/" + participant.health_sheet.name,
diff --git a/apps/registration/models.py b/apps/registration/models.py
index 3e12fce..3a603f8 100644
--- a/apps/registration/models.py
+++ b/apps/registration/models.py
@@ -159,7 +159,13 @@ class ParticipantRegistration(Registration):
 
     @property
     def under_18(self):
-        return (timezone.now().date() - self.birth_date).days < 18 * 365.24
+        important_date = timezone.now().date()
+        if self.team and self.team.participation.tournament:
+            important_date = self.team.participation.tournament.date_start
+            if self.team.participation.final:
+                from participation.models import Tournament
+                important_date = Tournament.final_tournament().date_start
+        return (important_date - self.birth_date).days < 18 * 365.24
 
     @property
     def type(self):  # pragma: no cover
diff --git a/tfjm/matrix.py b/tfjm/matrix.py
index 20732d6..3d7e48d 100644
--- a/tfjm/matrix.py
+++ b/tfjm/matrix.py
@@ -76,7 +76,7 @@ class Matrix:
         """
         client = await cls._get_client()
         resp = await client.get_avatar()
-        return resp.avatar_url if resp.status_code == 200 else resp
+        return resp.avatar_url if hasattr(resp, "avatar_url") else resp
 
     @classmethod
     @async_to_sync
diff --git a/tfjm/settings.py b/tfjm/settings.py
index 76f5f9b..0b13ce4 100644
--- a/tfjm/settings.py
+++ b/tfjm/settings.py
@@ -56,6 +56,7 @@ INSTALLED_APPS = [
     'address',
     'bootstrap_datepicker_plus',
     'crispy_forms',
+    'django_filters',
     'django_tables2',
     'haystack',
     'logs',