>>> My Info: Win7_64, Nightly 49, 32bit, ID 20160526082509 STR_1: 1. Open https://bugzilla.mozilla.org/skins/contrib/Mozilla/tabzilla.png 2. Clear cache in about:preferences#advanced -> Network, disable internet connection 3. Switch to the tab opened in Step 1 4. Right-click on the image, click "Save Image as...", press Enter to save image 5. Open downloads panel or "All downloads" (Ctrl+J) 6. Click close button near the download item created in Step 4 7.(bonus) Enable internet connection AR: Step 4 - new download item is created, it only shows progressbar Step 6 - no visible action Step 7 - downloads is canceled, and the item displays text "Canceled" ER: Step 6 - downloads should be canceled, and the item displays text "Canceled" (i.e. result of Step 7) Note: 1) I run into this issue on different sites from time to time, but never was able to reproduce it reliably, until I tested STR_1, and it was 100% reproducible. 2) This happens when I want to cancel download before connection is established. Actually, I don't know what happens in back end, but it's obvious that download stays in pending state and only displays progressbar until something happens. I referred to that "something" as a "propper initialization" in the summary. Please improve the summary with appropriate definitions. Anyway, sometimes it takes up to 20 seconds for download to start, so I don't have to be super fast