diff --git a/addons/website_sale_slides/views/website_sale_templates.xml b/addons/website_sale_slides/views/website_sale_templates.xml
index da20157fdd0..820c0c296fc 100644
--- a/addons/website_sale_slides/views/website_sale_templates.xml
+++ b/addons/website_sale_slides/views/website_sale_templates.xml
@@ -21,7 +21,7 @@
                     <span t-if="course.image_1920" t-field="course.image_1920" t-options="{'widget': 'image', 'class': 'my-2'}"/>
                     <img t-else="" class="img img-fluid my-2" src="/website_slides/static/src/img/channel-training-default.jpg"/>
                 </div>
-                <t t-set="invitation_link" t-value="course_memberships[course].invitation_link"/>
+                <t t-set="invitation_link" t-value="course_memberships[course].invitation_link if course in course_memberships else ''"/>
                 <div class="col-7">
                     <a t-att-href="invitation_link"><h3 t-out="course.name" class="m-2"/></a>
                     <div t-out="course.description_short" class="fw-light o_wslides_desc_truncate_2 ms-2"/>
@@ -31,7 +31,7 @@
                            <t t-if="course.total_time"> - </t><t t-out="course.total_slides"/> step(s)
                         </t>
                     </div>
-                    <a role="button" class="btn btn-primary ms-2 my-2" t-att-href="invitation_link">
+                    <a role="button" class="btn btn-primary ms-2 my-2" t-attf-class="btn btn-primary ms-2 my-2 #{'disabled' if not invitation_link else ''}" t-att-href="invitation_link">
                         Start Learning
                     </a>
                 </div>