Here’s a non-intuitive error from Excel.
run-time error '-21474417848 (80010108)' Automation Error - The object has disconnected from its clients'
I was getting this on a call to QueryTables.Add.Refresh. Sometimes I also received out-of-memory errors and sometimes Excel 2003 simply crashed.
I was sourcing from a CSV file with newline terminated lines. Excel was reading in the entire file and trying to treat it as a single record. Converting to CR/LF by running unix2dos on the server fixed the issue. Ultraedit could have fixed it on the Windows box as a one-time conversion, but this is going to run every day.