I use FF 48.0.1; some sites think I'm using Chrome; YOU think I'm not using FF at all. I've NEVER (knowingly) installed Chrome. Just now I was checking my add-ons. I was informed that my Adobe Acrobat NPAPI Plug-in, Version 15.016.20045 and my Silverlight Plug-in 5.1.41105.0 were both "known to be vulnerable and should be updated." For additional confirmation, I clicked on "Check to see if your plugins are up to date" at the top of the page. That took me to: https://www.mozilla.org/en-US/plugincheck/?utm_source=firefox-browser&utm_medium=firefox-browser&utm_campaign=plugincheck-update, which told me Currently the plugin check service is only available to Firefox users on desktop and Android. Your system may not meet the requirements for Firefox, but you can try one of these versions: Download Firefox — English (US) My computer is a MacBook Pro (Mid 2009); 2.8 GHz Intel Core 2 Duo; running OS X Yosemite, Version 10.10.5 What is going on? Thanks, Bob Here are my Installed Plugins: OpenH624 Video Codec provided by Cisco Systems, Inc. Shockwave Flash 22.0 r0 Widevine Content Description Module provided by Google Inc. Default Browser Helper IPhotoPhotocast iPhoto6 And the two I wrote about above, which were both "known to be vulnerable and should be updated": Adobe Acrobat NPAPI Plug-in, Version 15.016.20045 Silverlight Plug-in 5.1.41105.0