Be more careful about loading

plays/lib/vars.yml

@@ -1,15 +1,25 @@
 ---
+- name: Check if internal system variables exists
+  stat:
+    path: "{{ plugin_config_root }}/vars.yml"
+  register: vars_yml
+
+- name: Load internal system variables
+  no_log: true
+  when: vars_yml.stat.exists
+  include_vars:
+    file: "{{ plugin_config_root }}/vars.yml"
+
+- name: Check if the app config file exists
+  stat:
+    path: "{{ app_config_root }}/config.yml"
+  register: config_yml
+
 - name: Load unencrypted variables
   no_log: true
+  when: config_yml.stat.exists
   include_vars:
-    ignore_unknown_extensions: true
+    file: "{{ app_config_root }}/config.yml"
-    dir: "{{ item }}"
-    extensions:
-      - yml
-      - yaml
-  with_items:
-    - "{{ plugin_config_root }}"  # vars.yml system variables
-    - "{{ app_config_root }}"  # config.yml end-user variables
 
 - name: Check if a vault directory exists
   stat: