You can see such error message when you try to copy your site using Site Administrator for SharePoint. Very often a reason for it can be that when exporting a specific site might also export objects outside this site as not only the objects in the site are exported but also dependent objects like images referenced in pages by this site and the master page assigned to the site. Actually you can exclude such dependencies from copping:

  • open the "SharePoint Information Portal\SharePoint Browser\SpReorganization\ReorganizationAdapter.py" source file
  • find the "exp.Settings.ExcludeDependencies = False" string
  • change the False value to True
  • kill the ipy.exe process