A few days ago, I accidentally refreshed my firefox, so all my settings are gone. Then every time I downloaded stuffs, the download dialog will always pop up. But the 'do this automatically' setting is not there. I tried downloading different file format, .mkv, .rar, .doc, .pdf and it's all the same. Somehow firefox sees this as binary file. Any idea how to fix this? I'm using firefox 43.0.4 on Mac OS X 10.11.1