Fixed admin not detecting any existing users when Flex users are being used

CHANGELOG.md

@@ -7,6 +7,7 @@
     * Fixed admin cache to detect moved and deleted pages
     * Fixed avatar URLs with `?` in them being broken
     * Fixed issue saving page with language that was not exactly `2` or `5` chars long [#1667](https://github.com/getgrav/grav-plugin-admin/issues/1667)
+    * Fixed admin not detecting any existing users when Flex users are being used
 
 # v1.9.3
 ## 04/22/2019

classes/admin.php

@@ -480,11 +480,16 @@ class Admin
      */
     public static function doAnyUsersExist()
     {
-        // check for existence of a user account
+        $accounts = Grav::instance()['accounts'] ?? null;
+        if ($accounts instanceof \Countable) {
+            return $accounts->count() > 0;
+        }
+
+        // TODO: remove old way to check for existence of a user account (Grav < v1.6.9)
         $account_dir = $file_path = Grav::instance()['locator']->findResource('account://');
         $user_check = glob($account_dir . '/*.yaml');
 
-        return $user_check ? true : false;
+        return $user_check;
     }
 
     /**