diff --git a/group_vars/all/07_applications.yml b/group_vars/all/07_applications.yml
index 04258c36..5c89d26f 100644
--- a/group_vars/all/07_applications.yml
+++ b/group_vars/all/07_applications.yml
@@ -147,7 +147,7 @@ defaults_applications:
     version:            "latest"
     redirect_url:       "https://{{domains.keycloak}}/auth/realms/{{primary_domain}}/protocol/openid-connect/auth"  # The redirect URL for the OAuth2 flow. It should match the redirect URL configured in Keycloak.
     allowed_roles:      admin                                                                                       # Restrict it default to admin role. Use the vars/main.yml to open the specific role for other groups  
-    cookie_secret:      "{{applications.oauth2_proxy.cookie_secret}}"                                               # Default use wildcard for primary domain, subdomain client specific configuration in vars files in the roles is possible openssl rand -hex 16
+    cookie_secret: "{{ applications.oauth2_proxy.cookie_secret if applications.oauth2_proxy is defined else '' }}"  # Default use wildcard for primary domain, subdomain client specific configuration in vars files in the roles is possible openssl rand -hex 16
 
   ## Open Project
   openproject:
diff --git a/playbook.constructor.yml b/playbook.constructor.yml
index 2e1ab9d5..b833c184 100644
--- a/playbook.constructor.yml
+++ b/playbook.constructor.yml
@@ -15,7 +15,7 @@
         {{
           (defaults_redirect_domain_mappings | items2dict(key_name='source', value_name='target'))
           | combine(
-              (redirect_domain_mappings | items2dict(key_name='source', value_name='target')),
+              (redirect_domain_mappings | default([]) | items2dict(key_name='source', value_name='target')),
               recursive=True
             )
         }}
diff --git a/playbook.destructor.yml b/playbook.destructor.yml
index ee2e9a57..3c74b967 100644
--- a/playbook.destructor.yml
+++ b/playbook.destructor.yml
@@ -3,4 +3,4 @@
   become: true
   roles:
     - role: system-storage-optimizer
-      when: "(path_mass_storage is defined or path_rapid_storage is defined) and enable_system_storage_optimizer | bool"
+      when: "(path_mass_storage is defined or path_rapid_storage is defined) and enable_system_storage_optimizer | bool and (docker_enabled is defined and docker_enabled | bool) "
diff --git a/roles/docker/tasks/main.yml b/roles/docker/tasks/main.yml
index 82df296d..c6d8a632 100644
--- a/roles/docker/tasks/main.yml
+++ b/roles/docker/tasks/main.yml
@@ -16,6 +16,11 @@
     group: administrator
   when: run_once_docker is not defined
 
+- name: Set docker_enabled to true, to activate system-storage-optimizer 
+  set_fact:
+    docker_enabled: true
+  when: run_once_docker is not defined
+
 - name: flush docker service
   meta: flush_handlers
   when: run_once_docker is not defined