Receive Server Error while browsing the Exchange EWS or Autodiscover sites

Recently i received the following error while try to browse the following /autodiscover/Autodiscover.xml">https://<servername>/autodiscover/Autodiscover.xml  or /ews/exchange.asmx">https://<servername>/ews/exchange.asmx: Could not load file or assembly ‘Microsoft.Exchange.Diagnostics, Version=8.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35’ or one of its dependencies. The system cannot find the file specified. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace…