You sync a Microsoft SharePoint site to a SharePoint workspace by using Microsoft SharePoint Workspace.
The SharePoint site includes a list that contains attachments.
The list seems to sync successfully to the SharePoint workspace.
After the list has synchronized, you go offline and then open the list in the SharePoint workspace.
In this scenario, you may find that some list attachments are unavailable. Attachments smaller than 3 megabytes (MB) open while you are offline. However, attachments 3 MB or larger do not open. Instead, you receive the following error message:
Unable to open URL for attachment. Cannot locate the Internet server or proxy server
After you go back online, you can access these attachments from the SharePoint workspace.
Also, if you try to add an attachment of 3 MB or larger to the list in the workspace, you receive the following error message:
SharePoint Workspace cannot submit the form. An error occurred while the form was being submitted.
File size too large (filename).
The synchronization mechanism for lists in SharePoint Workspace is optimized for many small records. The mechanism does not support attachments larger than 3 MB. These attachments can be accessed when the workspace can connect to the SharePoint server. However, the attachments are never taken offline.
To work around this size limitation, store large files in a document library instead of as list attachments.