Error when loging to the dashboard, cannot view dashboard

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Hi

I recently transferred all my files from my primary domain to subdomain , via FTP. but while transferring the files , most of the concrete5 files were overwritten. I don't know why, because I am not so familiar with concrete5. Then after uploading all the files to the new subdomain , the site was up but the problem was I couldn't view the dashboard. when I login to the concrete5 dashboard an error is shown as below:

Fatal error: Call to undefined method Controller::view() in D:\Hosting\9267263\html\concrete\core\libraries\controller.php on line 219

Right now I cannot view the dashboard in my old site as well. I cannot update the content. And in my site , my uploaded pdf files are not working also the map, they are all showing the same error , so the customers are finding difficult to view the pdf files. don't know what has happened, please help me . As I am not an intelligent person in building website, just a beginner, any help would be much appreciated.

If any file is missing I need to re-upload the concrete files, please could anyone suggest , how I can do this , as I am just a beginner

Thanks for the help.