What is the correct path for vars_files in ansible controller?

My playbook has no issues when running it on the command line. But in ansible controller, I am encountering this error:

[WARNING]: Found variable using reserved name: vars_files

ERROR! vars file /var/lib/awx/projects/Windows/roles/create/vars/appendvars.yml was not found
Could not find file on the Ansible Controller.
If you are using a module and expect the file to exist on the remote, see the remote_src option

This is my playbook path:

/var/lib/awx/projects/Windows/playbook.yml

My playbook:

- name: Create from data
  hosts: localhost
  roles:
    - role: Create
  vars_files:
    - /var/lib/awx/projects/Windows/roles/Create/vars/appendvars.yml

- name: Delete from data
  hosts: localhost
  roles:
    - role: Delete
  vars_files:
    - /var/lib/awx/projects/Windows/roles/Delete/vars/appendvars.yml

Each of these vars_files contain the variables and their corresponding values, for me to reference the variable name in my playbook tasks.

I have already seen this question, https://stackoverflow.com/questions/56571594/error-vars-file-vars-not-found-on-the-ansible-controller , but I am still unable to resolve my issue.

In the 'variables' section of Ansible Controller, I have already tried these:

vars_files:
  - /roles/Create/vars/appendvars.yml
  - /roles/Delete/vars/appendvars.yml

vars_files:
  - appendvars.yml
  - appendvars.yml

vars_files:
  - /roles/Create/vars/appendvars.yml
  - /roles/Delete/vars/appendvars.yml

vars_files:
  - /var/lib/awx/projects/Windows/roles/Create/vars/appendvars.yml
  - /var/lib/awx/projects/Windows/roles/Delete/vars/appendvars.yml

But I still get the exact same error message. What and where do I need to change to fix this error?

Based on @β.εηοιτ.βε 's suggestions,

In /roles/Create/vars/main.yml, I removed:

vars_files:
  - /var/lib/awx/projects/Windows/roles/Create/vars/appendvars.yml

which was causing the warning: "[WARNING]: Found variable using reserved name: vars_files", and replaced it with all the variables from /roles/Create/vars/appendvars.yml

Did the same for the 'Delete' role too.

Correct playbook:

- name: Create from data
  hosts: localhost
  roles:
    - role: Create

- name: Delete from data
  hosts: localhost
  roles:
    - role: Delete