diff --git a/rc_hip/repapp/models.py b/rc_hip/repapp/models.py
index 4cf763a..c86d071 100644
--- a/rc_hip/repapp/models.py
+++ b/rc_hip/repapp/models.py
@@ -54,7 +54,7 @@ class Cafe(models.Model):
     address = models.CharField(
         max_length=200, verbose_name=_("Adresse"))
     event_date = models.DateField(verbose_name=_("Datum"))
-    reparateur = models.ManyToManyField(Reparateur)
+    reparateur = models.ManyToManyField(Reparateur, null=True)
 
     class Meta:
         verbose_name = _('Repair-Café')
@@ -138,7 +138,7 @@ class Device(models.Model):
         Guest, on_delete=models.CASCADE, null=True, verbose_name=_("Gast"), choices=STATUS)
     cafe = models.ForeignKey(
         Cafe, on_delete=models.CASCADE, null=False, verbose_name=_("Repair-Café"))
-    reparateur = models.ManyToManyField(Reparateur)
+    reparateur = models.ManyToManyField(Reparateur, null=True)
 
     class Meta:
         verbose_name = _('Gerät')
diff --git a/rc_hip/repapp/templates/repapp/orga/main.html b/rc_hip/repapp/templates/repapp/orga/main.html
index 0d44f7a..9d8eac9 100644
--- a/rc_hip/repapp/templates/repapp/orga/main.html
+++ b/rc_hip/repapp/templates/repapp/orga/main.html
@@ -17,8 +17,10 @@
     <h1 class="mt-2">Repair-Cafés</h1>
     <p>
         <a href="{% url 'create_cafe' %}" class="btn btn-primary">Neues Repair-Café anlegen</a>
-        <a href="{% url 'orga_plan_cafe' next_cafe.pk %}"
-           class="btn btn-primary">Nächstes Repair-Café</a>
+        {% if next_cafe %}
+            <a href="{% url 'orga_plan_cafe' next_cafe.pk %}"
+               class="btn btn-primary">Nächstes Repair-Café</a>
+        {% endif %}
     </p>
     <hr class="mt-0 mb-4">
     <h1 class="mt-2">Geräte</h1>