I ran into the same thing last night and again this morning. MS Windows Defender/Symantec Antivirus don't appear to like the new format on RCU. It's a shame as I really enjoy researching this site but it is not working well at all right now.

The format/layout of the pages seems to be somewhat different too. I presume they are trying an update on the site and it isn't going as well as they had hoped. I hope others chime in with their issues and those responsible for making decsions as to how the site operates remove all the intrusive snapins and downloaders they are trying to install on our computers. I went looking for a place to contact a moderator or even an SA and couldn't find any contact information under the "Help" page....