Just realized you have Episerver 7 so scratch my previous response :)
The edit/admin is located in the appdata folder for Episerver 7 and is updated like an addon. So probably you are missing some files there. Compare vs production site and copy everything there (it's located outside of www root). Also compare vs an alloy template site if you get into trouble. You need to copy both the www folder and the appData folder where protected addons are stored.
Great! What was it? Was it that the file was missing or error in config setting for appdata folder?
I am getting below exception when am login to CMS server. Immediately after login i am getting below exception.
Could not find a part of the path 'D:\MyApp\secure\Shell\2.1.118\ClientResources\packages.config'.