So if this happens
The search service is currently offline. Visit the Services on Server page in SharePoint Central Administration to verify whether the service is enabled. This might also be because an indexer move is in progress.
Troubleshoot issues with Windows SharePoint Services.</blockquote>
This is probably the reason: These issues occur if the out of box (OOB) default scopes on the shared service provider (SSP) are deleted. K, that’s all.