You attempted to check out one or more files from a SharePoint document library, but you received an error.
A checkout might fail for any of the following reasons:
You may have lost connectivity to the SharePoint server.
To test your connectivity, try going to the SharePoint site in a Web browser.
You may not have permission to check out the files on the SharePoint server. For more information, contact your SharePoint site administrator.
The files may have been deleted on the SharePoint server.
A SharePoint workspace automatically synchronizes with its corresponding SharePoint site over brief, regular intervals, depending on network traffic. In rare cases, you might attempt to check out files that were deleted on the SharePoint server during the period before the next synchronization. If you want to ensure that the files you want to check out still exist on the server, initiate a manual synchronization before attempting the checkout.