diff --git a/README.md b/README.md
index c413540..43ad0be 100644
--- a/README.md
+++ b/README.md
@@ -74,6 +74,8 @@ Here is a batch of usefull commands.
 docker compose down -v  # Remove volume containings results
 docker compose -f docker-compose-dev.yml up  # Start application in developpement mode
 rm -rf aperisolve/results  # Remove results from developpement mode
+docker exec -it postgres psql -U aperiuser -d aperisolve  # Get postgresql shell
+docker exec -it aperisolve-web bash # Get shell in running web app
 ```
 
 > Note, if you used [docker-compose-dev.yml](docker-compose-dev.yml), you must remove "results" when switching to [production docker](docker-compose.yml).
diff --git a/aperisolve/app.py b/aperisolve/app.py
index a66cf9e..8f070f0 100644
--- a/aperisolve/app.py
+++ b/aperisolve/app.py
@@ -38,6 +38,12 @@ def too_large(_: Any) -> tuple[Response, int]:
     return jsonify({"error": "Image size exceeded"}), 413
 
 
+@app.errorhandler(404)
+def not_found(_: Any) -> str:
+    """Error Handler for 404 not found."""
+    return render_template("error.html", message="Ressource not found", statuscode=404)
+
+
 @app.route("/")
 def index() -> str:
     """Render the main index page."""
diff --git a/aperisolve/cleanup.py b/aperisolve/cleanup.py
index be77581..48ea6a6 100644
--- a/aperisolve/cleanup.py
+++ b/aperisolve/cleanup.py
@@ -47,4 +47,9 @@ def cleanup_old_entries() -> None:
             shutil.rmtree(RESULT_FOLDER / img.hash)  # type: ignore
             db.session.delete(img)
 
+        # Delete Images with missing submission
+        if len(img.submissions) == 0 and delay > MAX_PENDING_TIME:
+            shutil.rmtree(RESULT_FOLDER / img.hash)  # type: ignore
+            db.session.delete(img)
+
     db.session.commit()
diff --git a/aperisolve/static/css/aperisolve.css b/aperisolve/static/css/aperisolve.css
index 79fd981..1d4c7be 100644
--- a/aperisolve/static/css/aperisolve.css
+++ b/aperisolve/static/css/aperisolve.css
@@ -407,4 +407,11 @@ footer a i {
 .glow-border {
     border: 1px solid var(--theme-green);
     box-shadow: 0 0 10px var(--theme-green-shadow);
+}
+
+#httperror{
+    padding-top: 100px;
+}
+#httperror h1, #httperror h2{
+    text-align: center;
 }
\ No newline at end of file
diff --git a/aperisolve/templates/error.html b/aperisolve/templates/error.html
new file mode 100644
index 0000000..903cef3
--- /dev/null
+++ b/aperisolve/templates/error.html
@@ -0,0 +1,8 @@
+{% extends 'base.html' %}
+{% block body_content %}
+<div id="httperror">
+  <h1>{{ statuscode }}</h1>
+  <br>
+  <h2>{{ message }}</h2>
+</div>
+{% endblock %}
\ No newline at end of file