SharePoint Error in Visual Studio Debugging a workflow: Operation aborted (Exception from HRESULT: 0x80004004 (E_ABORT))
Leave it to Microsoft to break every SharePoint Dev server in the world in one fell swoop.
When you go to debug a workflow from Visual Studio 2008, it builds fine, but on deploy, it fails while trying to attach to the list with this error:
Operation aborted (Exception from HRESULT: 0x80004004 (E_ABORT))
Causing the Error: Security patch KB2493987
If you have automatic updates set on your dev servers (which many people do), you will automatically get this security patch. And, it will break all your custom visual studio debugging abilities on all dev servers.
Solution: = Running the SharePoint Products and Technologies Configuration Wizard and doing an IISRESET.
For a full explanation, see this helpful post: http://deinfotech.blogspot.com/2011/09/sharepoint-2007errors-creating-site-and.html