Until a few days, whenever I opened a PDF file, the document would open flawlessly and present itself for view. A couple of days ago, when I try to open a PDF file nothing happens until:

Firefox is my default browser on a Windows 10 PC. I have Firefox version 67.0.4 , and Windows is updated to version 1809 (1809 amd64 2019-03). I have set Adobe Acrobat Reader as the default application to open PDF file. I have made no changes to settings this week ( week ending Fri 21 Mat 2019) Until a few days, whenever I opened a PDF file, the document would open flawlessly and present itself for view. A couple of days ago, when I try to open a PDF file nothing happens until: 1. I click the download button (the down arrow) 2. I have to manually select Adobe Reader even though that is already the default app in settings 3. Then click OK ... and finally the Adobe Acrobat PDF icon appears in the taskbar. The multiple steps suddenly necessary are driving me crazy (I open dozens of documents each hour) NONE of these steps were necessary a few days ago . (And they are also not necessary in Chrome). What has changed? -and- how do I get back to the previous Firefox browser behavior that just opened any and all PDF documents (without hesitation ). THANK YOU !