diff --git a/app/forms/main/config_logos.py b/app/forms/main/config_logos.py
index 2be78713d..c89983271 100644
--- a/app/forms/main/config_logos.py
+++ b/app/forms/main/config_logos.py
@@ -30,17 +30,15 @@ Formulaires configuration logos
 
 Contrib @jmp, dec 21
 """
-import re
 
 from flask import flash, url_for, redirect, render_template
 from flask_wtf import FlaskForm
 from flask_wtf.file import FileField, FileAllowed
-from wtforms import SelectField, SubmitField, FormField, validators, FieldList
+from wtforms import SubmitField, FormField, validators, FieldList
+from wtforms import ValidationError
 from wtforms.fields.simple import StringField, HiddenField
 
-from app import AccessDenied
 from app.models import Departement
-from app.models import ScoDocSiteConfig
 from app.scodoc import sco_logos, html_sco_header
 from app.scodoc import sco_utils as scu
 from app.scodoc.sco_config_actions import (
@@ -49,10 +47,11 @@ from app.scodoc.sco_config_actions import (
     LogoInsert,
 )
 
-from flask_login import current_user
 
+from app.scodoc import sco_utils as scu
 from app.scodoc.sco_logos import find_logo
 
+
 JAVASCRIPTS = html_sco_header.BOOTSTRAP_MULTISELECT_JS + []
 
 CSSSTYLES = html_sco_header.BOOTSTRAP_MULTISELECT_CSS
@@ -111,6 +110,15 @@ def dept_key_to_id(dept_key):
     return dept_key
 
 
+def logo_name_validator(message=None):
+    def validate_logo_name(form, field):
+        name = field.data if field.data else ""
+        if not scu.is_valid_filename(name):
+            raise ValidationError(message)
+
+    return validate_logo_name
+
+
 class AddLogoForm(FlaskForm):
     """Formulaire permettant l'ajout d'un logo (dans un département)"""
 
@@ -118,11 +126,7 @@ class AddLogoForm(FlaskForm):
     name = StringField(
         label="Nom",
         validators=[
-            validators.regexp(
-                r"^[a-zA-Z0-9-_]*$",
-                re.IGNORECASE,
-                "Ne doit comporter que lettres, chiffres, _ ou -",
-            ),
+            logo_name_validator("Nom de logo invalide (alphanumérique, _)"),
             validators.Length(
                 max=20, message="Un nom ne doit pas dépasser 20 caractères"
             ),
@@ -373,11 +377,11 @@ def config_logos():
         if action:
             action.execute()
             flash(action.message)
-            return redirect(
-                url_for(
-                    "scodoc.configure_logos",
-                )
-            )
+            return redirect(url_for("scodoc.configure_logos"))
+        else:
+            if not form.validate():
+                scu.flash_errors(form)
+
     return render_template(
         "config_logos.html",
         scodoc_dept=None,
diff --git a/app/scodoc/sco_utils.py b/app/scodoc/sco_utils.py
index 1cc6e89c0..b3d99ac3e 100644
--- a/app/scodoc/sco_utils.py
+++ b/app/scodoc/sco_utils.py
@@ -50,7 +50,7 @@ import pydot
 import requests
 
 from flask import g, request
-from flask import url_for, make_response, jsonify
+from flask import flash, url_for, make_response, jsonify
 
 from config import Config
 from app import log
@@ -616,6 +616,16 @@ def bul_filename(sem, etud, format):
     return filename
 
 
+def flash_errors(form):
+    """Flashes form errors (version sommaire)"""
+    for field, errors in form.errors.items():
+        flash(
+            "Erreur: voir le champs %s" % (getattr(form, field).label.text,),
+            "warning",
+        )
+        # see https://getbootstrap.com/docs/4.0/components/alerts/
+
+
 def sendCSVFile(data, filename):  # DEPRECATED  utiliser send_file
     """publication fichier CSV."""
     return send_file(data, filename=filename, mime=CSV_MIMETYPE, attached=True)
diff --git a/app/templates/base.html b/app/templates/base.html
index adf70171b..c4083a53c 100644
--- a/app/templates/base.html
+++ b/app/templates/base.html
@@ -57,12 +57,10 @@
 
 {% block content %}
 <div class="container">
-    {% with messages = get_flashed_messages() %}
-    {% if messages %}
-    {% for message in messages %}
-    <div class="alert alert-info" role="alert">{{ message }}</div>
-    {% endfor %}
-    {% endif %}
+    {% with messages = get_flashed_messages(with_categories=true) %}
+        {% for category, message in messages %}
+            <div class="alert alert-info alert-{{ category }}" role="alert">{{ message }}</div>
+        {% endfor %}
     {% endwith %}
 
     {# application content needs to be provided in the app_content block #}
diff --git a/app/templates/sco_page.html b/app/templates/sco_page.html
index d3fbdcf87..e1aa9e3c5 100644
--- a/app/templates/sco_page.html
+++ b/app/templates/sco_page.html
@@ -23,12 +23,10 @@
 
 <div id="gtrcontent" class="gtrcontent">
     <div class="container">
-        {% with messages = get_flashed_messages() %}
-        {% if messages %}
-        {% for message in messages %}
-        <div class="alert alert-info" role="alert">{{ message }}</div>
-        {% endfor %}
-        {% endif %}
+        {% with messages = get_flashed_messages(with_categories=true) %}
+            {% for category, message in messages %}
+                <div class="alert alert-info alert-{{ category }}" role="alert">{{ message }}</div>
+            {% endfor %}
         {% endwith %}
     </div>
     {% if sco.sem %}