To display the proper error messages in the SharePoint Site

1. On the Web server, navigate to the site directory:Local Drive:\Inetpub\wwwroot\wss\VirtualDirectories\[directory for site] (for example 84)
2. Open Web.config in Notepad.
3. Search for "CallStack". Change the CallStack status to "true".
4. Search for "CustomErrors". Change the mode to "off".
5. Save and close the file.