SqlBulkCopy.WriteToServer() keep getting “connection is closed”

Question

This makes no sense to me but maybe someone with keener eyes can spot the problem.

I have a Windows service that uses FileSystemWatcher. It processes some files and upl

Answer 1

Way late to throw this one on here but I was having what I thought was the same issue with SqlBulkCopy. Tried some of the steps in the other answers but with no luck. Turns out in my case that the actual error was caused by a string in the data going above the max length on one of the varchar columns, but for some reason the only error I was getting was the one about the closed connection.

Strangely, my coworker tried the same thing, and got an actual error message about the varchar being out of bounds. So we fixed the data and everything worked, but if you're here because of this error and nothing else works, you might want to start looking for different issues in your data.