How to see the actual error in SharePoint

In order to see the actual error you need to make a few modifications of web.config file. Take the web.config file from application\site that gives the error.

Open in Notepad:
First, change customErrors mode in "Off"

Second, change CallStack="true"

Refresh the page with error

FatalError: Could not find Feature S2SiteAdmin.

I was importing one of my site and I got the next message:

Problem:

Progress: Initializing Import.

FatalError: Could not find Feature S2SiteAdmin.

Solution:

You need to install "Infrastructure Update for Microsoft Office Servers (KB951297)"

Brief Description

The Infrastructure Update for Microsoft Office Servers (KB951297) includes the latest performance updates and fixes for the Microsoft Office Servers.

Download

How to create host name top level site with stsadm

For example, if you have a Web application named http://sharepoint.com and you want to add a host-named site collection with the URL http://about.sharepoint.com, use the following command:

stsadm.exe -o createsite -url http://about.sharepoint.com -ownerlogin domain\siteowner -owneremail siteowner@sharepoint.com -hhurl http://sharepoint.com

Renaming Site
stsadm -o renamesite -oldUrl http://www.name.com -newUrl http://www.newname.com