old_contents: from flask import Blueprint
  
  public = Blueprint('public', __name__, template_folder='templates')
  
  
  @public.route('/')
  def index():
      return 'Hello World'
  
new_contents: from flask import Blueprint
  
  public = Blueprint('public', __name__)
  
  
  @public.route('/')
  def index():
      return 'Hello World'
  
subject: Remove blueprint specific template directories.