Fatal error: Cannot access protected property JRouterSite::$_mo

Need help my mobile website cannot view 

error : Fatal error: Cannot access protected property JRouterSite::$_mode in E:\xampp\htdocs\mlib\plugins\system\mobile\mobile.php on line 397

: (

What is plugins\system\mobile\mobile.php plugin? MobileJoomla has no such a plugin.

yup plugins\system\mobile\mobile.php on line 397

what plugin i need to install?

I don't know what plugin is located at plugins\system\mobile\mobile.php, but sure it's not MobileJoomla plugin.
What system group plugins do you have installed?

script :

$app =& JFactory::getApplication();
$suffix = $app->getCfg('sef_suffix');

$jroute = $app->getRouter();
$sef = $jroute->_mode;<---Fatal error: Cannot access protected property JRouterSite::$_mode in E:plugins\system\mobile\mobile.php on line 397

/*
JRoute:
define('JROUTER_MODE_RAW', 0);
define('JROUTER_MODE_SEF', 1);
*/

plug in i install


please advice me if my mistake  

Uninstall or disable "Mobile plugin" plugin.

after disable i got dis error:404





Please advice me if i do mistake 

Try to clear cookies, maybe it helps.

What is content of plugins/system/mobile/mobile.xml? It should contain URL of plugin developer.

this is inside mobile.xml