Unusual exception - reading/updating Excel spread sheet

I am reading content of a full spread sheet to a datatable

Then iterate through Table.Rows Query Remote database (Oracle), and Create/Update/Delete ADS account

Then update the Excel row with the result (status)

Most of the time things go smoothly, but intermittently I get this exception:

ContextSwitchDeadlock w开发者_运维知识库as detected

Message: The CLR has been unable to transition from COM context 0x2119a8 to COM context 0x211b18 for 60 seconds. The thread that owns the destination context/apartment is most likely either doing a non pumping wait or processing a very long running operation without pumping Windows messages.

This situation generally has a negative performance impact and may even lead to the application becoming non responsive or memory usage accumulating continually over time. To avoid this problem, all single threaded apartment (STA) threads should use pumping wait primitives (such as CoWaitForMultipleHandles) and routinely pump messages during long running operations.

What could be causing this ?