diff --git a/includes/lib_remote.php b/includes/lib_remote.php
index aafb450e..1f206cbb 100644
--- a/includes/lib_remote.php
+++ b/includes/lib_remote.php
@@ -24,6 +24,24 @@
 
 require_once("Crypt/XXTEA.php");
 
+if (!defined('GSP_XMLRPC_READY')) {
+	if (!function_exists('xmlrpc_encode_request') || !function_exists('xmlrpc_decode')) {
+		$message = "GSP requires the PHP xmlrpc extension for agent communication.\n".
+		           "Install the php-xmlrpc package for your PHP version (example: sudo apt install php8.3-xmlrpc on Ubuntu 24.04 or use PECL).\n".
+		           "See https://www.php.net/manual/en/book.xmlrpc.php for installation instructions.";
+		if (PHP_SAPI === 'cli') {
+			fwrite(STDERR, $message . PHP_EOL);
+		} else {
+			if (!headers_sent()) {
+				header('Content-Type: text/plain; charset=UTF-8', true, 500);
+			}
+			echo nl2br(htmlentities($message));
+		}
+		exit(1);
+	}
+	define('GSP_XMLRPC_READY', true);
+}
+
 // Screen type for servers
 define("OGP_SCREEN_TYPE_HOME","HOME");
 define("OGP_SCREEN_TYPE_UPDATE","UPDATE");
diff --git a/modules/billing/admin.php b/modules/billing/admin.php
index 7512ab87..8139bcfe 100644
--- a/modules/billing/admin.php
+++ b/modules/billing/admin.php
@@ -1,7 +1,7 @@
 <?php
 // Admin landing page
 require_once(__DIR__ . '/includes/admin_auth.php');
-require_once(__DIR__ . '/includes/config.inc.php');
+require_once(__DIR__ . '/includes/config_loader.php');
 include(__DIR__ . '/includes/top.php');
 include(__DIR__ . '/includes/menu.php');
 
diff --git a/modules/billing/admin_config.php b/modules/billing/admin_config.php
index dd30a966..dbbe2fea 100644
--- a/modules/billing/admin_config.php
+++ b/modules/billing/admin_config.php
@@ -1,7 +1,7 @@
 <?php
 // Admin config editor — lightweight editor for _website/includes/config.inc.php
 require_once(__DIR__ . '/includes/admin_auth.php');
-require_once(__DIR__ . '/includes/config.inc.php');
+require_once(__DIR__ . '/includes/config_loader.php');
 include(__DIR__ . '/includes/top.php');
 include(__DIR__ . '/includes/menu.php');
 
diff --git a/modules/billing/admin_coupons.php b/modules/billing/admin_coupons.php
index 12a39375..816ea87f 100644
--- a/modules/billing/admin_coupons.php
+++ b/modules/billing/admin_coupons.php
@@ -1,7 +1,7 @@
 <?php
 // Admin coupon management page - standalone billing module
 require_once(__DIR__ . '/includes/admin_auth.php');
-require_once(__DIR__ . '/includes/config.inc.php');
+require_once(__DIR__ . '/includes/config_loader.php');
 
 // Variables from config.inc.php (helps IDEs understand scope)
 /** @var string $db_host Database host */
diff --git a/modules/billing/admin_payments.php b/modules/billing/admin_payments.php
index 7fcfa1c7..04e39386 100644
--- a/modules/billing/admin_payments.php
+++ b/modules/billing/admin_payments.php
@@ -1,7 +1,7 @@
 <?php
 // Admin payments viewer — lists persisted PayPal webhook JSON files
 $session_name = session_name(); session_start();
-require_once(__DIR__ . '/includes/config.inc.php');
+require_once(__DIR__ . '/includes/config_loader.php');
 require_once(__DIR__ . '/includes/admin_auth.php');
 
 $dataDir = (isset($SITE_DATA_DIR) && $SITE_DATA_DIR) ? $SITE_DATA_DIR : realpath(__DIR__ . '/') . DIRECTORY_SEPARATOR . 'data';
diff --git a/modules/billing/api/capture_order.php b/modules/billing/api/capture_order.php
index 8c913564..3ab5f447 100644
--- a/modules/billing/api/capture_order.php
+++ b/modules/billing/api/capture_order.php
@@ -5,7 +5,7 @@
  * Standalone billing module - uses only standard PHP mysqli
  */
 
-require_once(__DIR__ . '/../includes/config.inc.php');
+require_once(__DIR__ . '/../includes/config_loader.php');
 
 // Prevent any output before JSON
 ob_start();
diff --git a/modules/billing/api/create_order.php b/modules/billing/api/create_order.php
index 33cd06b7..2042df6b 100644
--- a/modules/billing/api/create_order.php
+++ b/modules/billing/api/create_order.php
@@ -8,7 +8,7 @@
 ini_set('display_errors', '0');
 error_reporting(E_ALL);
 
-require_once(__DIR__ . '/../includes/config.inc.php');
+require_once(__DIR__ . '/../includes/config_loader.php');
 // create_order for PayPal — adapted to run from _website/api
 $sandbox       = true; // flip to false for Live
 $client_id     = 'AfvY_C2zA_hTHxHq7TIhtOeub4xBdySYrt_Hjj3d_WYQwjWI9NfOAVOTeResx2rgZ_nP5tOoxQSAHw8c';
diff --git a/modules/billing/bootstrap.php b/modules/billing/bootstrap.php
index 6684808c..0750d843 100644
--- a/modules/billing/bootstrap.php
+++ b/modules/billing/bootstrap.php
@@ -5,14 +5,7 @@
 
 // Ensure session sync with panel happens first
 require_once __DIR__ . '/includes/session_bridge.php';
-
-// Load configuration (includes/config.inc.php) if present
-$config_path = __DIR__ . '/includes/config.inc.php';
-if (file_exists($config_path)) {
-    require_once $config_path;
-} else {
-    trigger_error('Billing config not found: ' . $config_path, E_USER_WARNING);
-}
+require_once __DIR__ . '/includes/config_loader.php';
 
 // Ensure $table_prefix exists (fallback to empty string)
 if (!isset($table_prefix)) {
diff --git a/modules/billing/diag_remote.php b/modules/billing/diag_remote.php
index 6574d334..57da2096 100644
--- a/modules/billing/diag_remote.php
+++ b/modules/billing/diag_remote.php
@@ -21,15 +21,19 @@ echo "Session status (after start): " . session_status() . "\n";
 echo "Session id: " . session_id() . "\n";
 echo "Session variables: \n" . print_r($_SESSION, true) . "\n";
 
-// Check config file readability
-$cfg = __DIR__ . '/includes/config.inc.php';
-echo "Config file: " . $cfg . " exists=" . (file_exists($cfg) ? 'yes' : 'no') . " readable=" . (is_readable($cfg) ? 'yes' : 'no') . "\n";
-if (file_exists($cfg)) {
-    echo "Config contents (first 200 chars):\n" . substr(file_get_contents($cfg),0,200) . "\n";
+// Check config file readability (panel root first, module local second)
+$panelCfgRoot = realpath(__DIR__ . '/../../..');
+$panelCfg = $panelCfgRoot ? $panelCfgRoot . '/includes/config.inc.php' : __DIR__ . '/../../..' . '/includes/config.inc.php';
+$localCfg = __DIR__ . '/includes/config.inc.php';
+echo "Panel config: " . $panelCfg . " exists=" . (file_exists($panelCfg) ? 'yes' : 'no') . " readable=" . (is_readable($panelCfg) ? 'yes' : 'no') . "\n";
+echo "Local config: " . $localCfg . " exists=" . (file_exists($localCfg) ? 'yes' : 'no') . " readable=" . (is_readable($localCfg) ? 'yes' : 'no') . "\n";
+
+require_once(__DIR__ . '/includes/config_loader.php');
+echo "Active config source: " . (defined('BILLING_CONFIG_PATH') ? BILLING_CONFIG_PATH : '(unknown)') . "\n";
+if (defined('BILLING_CONFIG_PATH') && is_readable(BILLING_CONFIG_PATH)) {
+    echo "Active config preview (first 200 chars):\n" . substr(file_get_contents(BILLING_CONFIG_PATH), 0, 200) . "\n";
 }
 
-// Attempt DB connection using site config (if readable)
-if (file_exists($cfg)) require_once($cfg);
 echo "Trying DB connection...\n";
 $ok = false;
 if (isset($db_host)) {
diff --git a/modules/billing/docs.php b/modules/billing/docs.php
index 160954f2..f2990a77 100644
--- a/modules/billing/docs.php
+++ b/modules/billing/docs.php
@@ -11,7 +11,7 @@ if (session_status() === PHP_SESSION_NONE) {
 }
 
 // Include config
-require_once(__DIR__ . '/includes/config.inc.php');
+require_once(__DIR__ . '/includes/config_loader.php');
 
 // Set the docs directory
 $docsDir = __DIR__ . '/docs';
diff --git a/modules/billing/docs/xml_notes.php b/modules/billing/docs/xml_notes.php
index ef73f373..6eb69a89 100644
--- a/modules/billing/docs/xml_notes.php
+++ b/modules/billing/docs/xml_notes.php
@@ -1,6 +1,6 @@
 <?php
 require_once(__DIR__ . '/../includes/admin_auth.php');
-require_once(__DIR__ . '/../includes/config.inc.php');
+require_once(__DIR__ . '/../includes/config_loader.php');
 include(__DIR__ . '/../includes/top.php');
 include(__DIR__ . '/../includes/menu.php');
 
diff --git a/modules/billing/includes/admin_auth.php b/modules/billing/includes/admin_auth.php
index 293375d4..5cbec4ad 100644
--- a/modules/billing/includes/admin_auth.php
+++ b/modules/billing/includes/admin_auth.php
@@ -20,8 +20,7 @@ if (empty($_SESSION['website_user_id'])) {
 }
 
 // Require DB config and check role live from panel DB
-
-require_once(__DIR__ . '/config.inc.php');
+require_once(__DIR__ . '/config_loader.php');
 
 // Variables from config.inc.php (helps IDEs understand scope)
 /** @var string $db_host Database host */
diff --git a/modules/billing/includes/config_loader.php b/modules/billing/includes/config_loader.php
new file mode 100644
index 00000000..c24ce314
--- /dev/null
+++ b/modules/billing/includes/config_loader.php
@@ -0,0 +1,64 @@
+<?php
+/**
+ * Billing config loader
+ *
+ * Attempts to load the main panel config file first (../includes/config.inc.php).
+ * If that file is not readable, falls back to a module-local config.inc.php copy.
+ * When neither file exists, output a plain-text error and stop execution so that
+ * the admin knows to copy the config locally.
+ */
+if (defined('BILLING_CONFIG_LOADED')) {
+    return;
+}
+
+$panelConfig = null;
+$projectRoot = realpath(__DIR__ . '/../../..');
+if ($projectRoot !== false) {
+    $panelConfig = $projectRoot . '/includes/config.inc.php';
+} else {
+    // Fallback relative path without resolving symlinks
+    $panelConfig = __DIR__ . '/../../..' . '/includes/config.inc.php';
+}
+
+$localConfig = __DIR__ . '/config.inc.php';
+$attempted = [];
+
+if ($panelConfig && is_readable($panelConfig)) {
+    $attempted[] = $panelConfig;
+    require_once $panelConfig;
+    if (!defined('BILLING_CONFIG_PATH')) {
+        define('BILLING_CONFIG_PATH', $panelConfig);
+    }
+    define('BILLING_CONFIG_LOADED', true);
+    return;
+}
+
+$attempted[] = $panelConfig;
+if (is_readable($localConfig)) {
+    $attempted[] = $localConfig;
+    require_once $localConfig;
+    if (!defined('BILLING_CONFIG_PATH')) {
+        define('BILLING_CONFIG_PATH', $localConfig);
+    }
+    define('BILLING_CONFIG_LOADED', true);
+    return;
+}
+
+$attempted[] = $localConfig;
+
+$message = "GSP Billing module cannot find config.inc.php.\n";
+$message .= "Looked in:\n";
+foreach ($attempted as $path) {
+    if (!$path) {
+        continue;
+    }
+    $message .= " - " . $path . "\n";
+}
+$message .= "\nCopy your panel's includes/config.inc.php into modules/billing/includes/config.inc.php ";
+$message .= "or ensure the panel config is readable so the billing pages can load database settings.\n";
+
+if (!headers_sent()) {
+    header('Content-Type: text/plain; charset=UTF-8', true, 500);
+}
+echo $message;
+exit(1);
diff --git a/modules/billing/includes/menu.php b/modules/billing/includes/menu.php
index c5b979f0..8e278dc4 100644
--- a/modules/billing/includes/menu.php
+++ b/modules/billing/includes/menu.php
@@ -22,7 +22,7 @@ if (isset($_SESSION['website_username']) && !empty($_SESSION['website_username']
 $is_admin = false;
 if ($is_logged_in) {
   // load DB credentials
-  require_once(__DIR__ . '/config.inc.php');
+  require_once(__DIR__ . '/config_loader.php');
   
   // Variables from config.inc.php (helps IDEs understand scope)
   /** @var string $db_host Database host */
diff --git a/modules/billing/includes/payment_processor.php b/modules/billing/includes/payment_processor.php
index bedd5e39..06aa6d74 100644
--- a/modules/billing/includes/payment_processor.php
+++ b/modules/billing/includes/payment_processor.php
@@ -12,14 +12,8 @@
  *   process_payment_record($record);
  */
 
-// Include the module-local config (must be present in the module includes folder).
-// Use ONLY `config.inc.php` — do NOT fall back to other filenames.
-$moduleConfig = __DIR__ . '/config.inc.php';
-if (is_file($moduleConfig)) {
-    require_once $moduleConfig;
-} else {
-    error_log('[payment_processor] Module config not found: expected ' . $moduleConfig);
-}
+// Load panel config first, falling back to a module-local copy if needed.
+require_once __DIR__ . '/config_loader.php';
 
 // Variables from config.inc.php (helps IDEs understand scope)
 /** @var string $db_host Database host */
@@ -226,3 +220,4 @@ function process_payment_record(array $record) {
 }
 
 ?>
+
diff --git a/modules/billing/invoices.php b/modules/billing/invoices.php
index b11c6145..ef1ff88d 100644
--- a/modules/billing/invoices.php
+++ b/modules/billing/invoices.php
@@ -1,7 +1,7 @@
 <?php
 // User invoice history (reads payments/data/*.json)
 $session_name = session_name(); session_start();
-require_once(__DIR__ . '/includes/config.inc.php');
+require_once(__DIR__ . '/includes/config_loader.php');
 // Intentionally do not require login here; invoices should be viewable (or filtered) without forcing a login.
 
 // try to get logged-in user's email for matching
diff --git a/modules/billing/payment_cancel.php b/modules/billing/payment_cancel.php
index 0d079f24..7c8c9878 100644
--- a/modules/billing/payment_cancel.php
+++ b/modules/billing/payment_cancel.php
@@ -6,7 +6,7 @@
 
 session_start();
 require_once(__DIR__ . '/includes/header.php');
-require_once(__DIR__ . '/includes/config.inc.php');
+require_once(__DIR__ . '/includes/config_loader.php');
 
 $invoice_ref = isset($_GET['invoice']) ? $_GET['invoice'] : '';
 
diff --git a/modules/billing/payment_success.php b/modules/billing/payment_success.php
index d467e0b2..6cb35620 100644
--- a/modules/billing/payment_success.php
+++ b/modules/billing/payment_success.php
@@ -5,7 +5,7 @@
  * Standalone billing module - uses only standard PHP mysqli
  */
 session_start();
-require_once(__DIR__ . '/includes/config.inc.php');
+require_once(__DIR__ . '/includes/config_loader.php');
 
 // Variables from config.inc.php (helps IDEs understand scope)
 /** @var string $db_host Database host */
@@ -223,4 +223,4 @@ if ($db && $user_id > 0) {
         </div>
     </div>
 </body>
-</html>
\ No newline at end of file
+</html>
diff --git a/modules/billing/return.php b/modules/billing/return.php
index cdb3f314..922f20b0 100644
--- a/modules/billing/return.php
+++ b/modules/billing/return.php
@@ -1,5 +1,5 @@
 <?php
-require_once(__DIR__ . '/includes/config.inc.php');
+require_once(__DIR__ . '/includes/config_loader.php');
 
 $dataDir = (isset($SITE_DATA_DIR) && $SITE_DATA_DIR) ? $SITE_DATA_DIR : realpath(__DIR__ . '/') . DIRECTORY_SEPARATOR . 'data';
 $invoice = $_GET['invoice'] ?? '';
diff --git a/modules/billing/tools/check_db_user.php b/modules/billing/tools/check_db_user.php
index 1d829ece..7c579605 100644
--- a/modules/billing/tools/check_db_user.php
+++ b/modules/billing/tools/check_db_user.php
@@ -1,5 +1,5 @@
 <?php
-require_once(__DIR__ . '/../includes/config.inc.php');
+require_once(__DIR__ . '/../includes/config_loader.php');
 $db = mysqli_connect($db_host, $db_user, $db_pass, $db_name);
 if (!$db) {
     echo "DB connect failed: " . mysqli_connect_error() . PHP_EOL;
@@ -27,4 +27,4 @@ if (mysqli_num_rows($res) === 0) {
     echo "pass_hash(db)=" . ($row['users_pass_hash'] ?? '') . "\n";
 }
 mysqli_close($db);
-?>
\ No newline at end of file
+?>
diff --git a/modules/billing/webhook.php b/modules/billing/webhook.php
index cf628247..b51c95e5 100644
--- a/modules/billing/webhook.php
+++ b/modules/billing/webhook.php
@@ -1,5 +1,5 @@
 <?php
-require_once(__DIR__ . '/includes/config.inc.php');
+require_once(__DIR__ . '/includes/config_loader.php');
 if (is_file(__DIR__ . '/includes/log.php')) require_once(__DIR__ . '/includes/log.php');
 
 $config = [