i have installed joomla application in my hosting company. However everytime i log in at joomla administration i received this error message:

Fatal error: Call to a member function login() on a non-object in /home/content/88/8127088/html/administrator/components/com_login/admin.login.php on line 63

I have installed and uninstalled the joomla aplications but still i get the same error message.

My hosting campany does not provide coding and scripting service. Please help what do i do?