Canceling

Click on the "Stop" button near the bottom of the window's center column to halt pending operations.

If multiple transactions have been queued, you will be asked whether to cancel only the one currently in progress or the entire queue.  The current transaction will continue while you are deciding, but no new transactions will be started until you have answered the question.

Interrupted transfers may be resumeable.  See the sections on Resuming Downlooads and Resuming Uploads for details.  Pack operations cannot be resumed.