diff --git a/classes/exception/PrestaShopException.php b/classes/exception/PrestaShopException.php
index 465bf0ddd..7cc56f203 100644
--- a/classes/exception/PrestaShopException.php
+++ b/classes/exception/PrestaShopException.php
@@ -66,14 +66,15 @@ class PrestaShopExceptionCore extends Exception
 				echo '<b>'.((isset($trace['class'])) ? $trace['class'] : '').((isset($trace['type'])) ? $trace['type'] : '').$trace['function'].'</b>';
 				echo ' - <a href="#" style="font-size: 12px; color: #000000" onclick="document.getElementById(\'psTrace_'.$id.'\').style.display = (document.getElementById(\'psTrace_'.$id.'\').style.display != \'block\') ? \'block\' : \'none\'; return false">[line '.$current_line.' - '.$relative_file.']</a>';
 
-				if (count($trace['args']))
+				if (isset($trace['args']) && count($trace['args']))
 					echo ' - <a href="#" onclick="document.getElementById(\'psArgs_'.$id.'\').style.display = (document.getElementById(\'psArgs_'.$id.'\').style.display != \'block\') ? \'block\' : \'none\'; return false">['.count($trace['args']).' Arguments]</a>';
 				else
 					echo ' - <span style="font-size: 12px;">[0 Argument]</a>';
 
 				if ($relative_file)
 					$this->displayFileDebug($trace['file'], $trace['line'], $id);
-				$this->displayArgsDebug($trace['args'], $id);
+				if (isset($trace['args']) && count($trace['args']))
+					$this->displayArgsDebug($trace['args'], $id);
 				echo '</li>';
 			}
 			echo '</ul>';
diff --git a/config/config.inc.php b/config/config.inc.php
index 763f3a135..2713c2a39 100644
--- a/config/config.inc.php
+++ b/config/config.inc.php
@@ -93,13 +93,15 @@ $context = Context::getContext();
 try 
 {
 	$context->shop = Shop::initialize();
+	if (Tools::isEmpty($theme_name = $context->shop->getTheme()) || !file_exists(_PS_ALL_THEMES_DIR_.$theme_name))
+		throw new PrestaShopException('No theme selected');
 }
 catch (PrestaShopException $e)
 {
 	$e->displayMessage();
 }
 
-define('_THEME_NAME_', $context->shop->getTheme());
+define('_THEME_NAME_', $theme_name);
 define('__PS_BASE_URI__', $context->shop->getBaseURI());
 
 /* Include all defines related to base uri and theme name */