diff --git a/lib/Froxlor/Api/Commands/Customers.php b/lib/Froxlor/Api/Commands/Customers.php
index 1f5bba68..348aa640 100644
--- a/lib/Froxlor/Api/Commands/Customers.php
+++ b/lib/Froxlor/Api/Commands/Customers.php
@@ -897,7 +897,9 @@ class Customers extends \Froxlor\Api\ApiCommand implements \Froxlor\Api\Resource
 			$email = $idna_convert->encode(\Froxlor\Validate\Validate::validate($email, 'email', '', '', array(), true));
 			$customernumber = \Froxlor\Validate\Validate::validate($customernumber, 'customer number', '/^[A-Za-z0-9 \-]*$/Di', '', array(), true);
 			$custom_notes = \Froxlor\Validate\Validate::validate(str_replace("\r\n", "\n", $custom_notes), 'custom_notes', '/^[^\0]*$/', '', array(), true);
-			$allowed_phpconfigs = array_map('intval', $allowed_phpconfigs);
+			if (!empty($allowed_phpconfigs)) {
+				$allowed_phpconfigs = array_map('intval', $allowed_phpconfigs);
+			}
 		}
 		$def_language = \Froxlor\Validate\Validate::validate($def_language, 'default language', '', '', array(), true);
 		$theme = \Froxlor\Validate\Validate::validate($theme, 'theme', '', '', array(), true);
diff --git a/lib/Froxlor/Database/Manager/DbManagerMySQL.php b/lib/Froxlor/Database/Manager/DbManagerMySQL.php
index 2014ae60..5919bd72 100644
--- a/lib/Froxlor/Database/Manager/DbManagerMySQL.php
+++ b/lib/Froxlor/Database/Manager/DbManagerMySQL.php
@@ -192,8 +192,13 @@ class DbManagerMySQL
 	 */
 	public function enableUser($username = null, $host = null)
 	{
-		Database::query('GRANT ALL PRIVILEGES ON `' . $username . '`.* TO `' . $username . '`@`' . $host . '`');
-		Database::query('GRANT ALL PRIVILEGES ON `' . str_replace('_', '\_', $username) . '` . * TO `' . $username . '`@`' . $host . '`');
+		// check whether user exists to avoid errors
+		$exist_check_stmt = Database::prepare("SELECT EXISTS(SELECT 1 FROM mysql.user WHERE user = '" . $username . "' AND host = '" . $host . "')");
+		$exist_check = Database::pexecute_first($exist_check_stmt);
+		if ($exist_check && array_pop($exist_check) == '1') {
+			Database::query('GRANT ALL PRIVILEGES ON `' . $username . '`.* TO `' . $username . '`@`' . $host . '`');
+			Database::query('GRANT ALL PRIVILEGES ON `' . str_replace('_', '\_', $username) . '` . * TO `' . $username . '`@`' . $host . '`');
+		}
 	}
 
 	/**
diff --git a/lib/Froxlor/Settings/Store.php b/lib/Froxlor/Settings/Store.php
index 86fba687..5c567d31 100644
--- a/lib/Froxlor/Settings/Store.php
+++ b/lib/Froxlor/Settings/Store.php
@@ -305,11 +305,11 @@ class Store
 
 			// be aware that ipv6 addresses are enclosed in [ ] when passed here
 			$mysql_access_host_array = array_map(array(
-				self,
+				'\\Froxlor\\Settings\\Store',
 				'cleanMySQLAccessHost'
 			), $mysql_access_host_array);
 
-			$mysql_access_host_array = array_unique(\Froxlor\PhpHelper::arrayTrim($mysql_access_host_array));
+			$mysql_access_host_array = array_unique($mysql_access_host_array);
 			$newfieldvalue = implode(',', $mysql_access_host_array);
 			\Froxlor\Database\DbManager::correctMysqlUsers($mysql_access_host_array);
 		}