This has been discovered and is affecting most of the open source implementations of virtualization environments. Vulnerability is called VENOM.
More information in here.
I am not sure what has happened to this PDF viewer, but this application has grew up to nearly 650MB!
What is it hiding in this software if alternative PDF viewers have just 35MB?
It is all sorts of corporate crap that sits there completely inactive unless you buy pro extended version of it.
The performance of this viewer is also going down.
Try the alternatives like SlimPDF or Foxit Reader.
They do some nice stickers in US that you can stick over Windows symbol (Win key), but why to do that?
SammieV from Canada perfectly answers this: “I love that symbol, it reminds me of why I moved over to another OS.”
Windows same as KERNAL, Commodore Basic or DOS is our heritage like inventions of Ancient and Medieval times and I do have very good memories of Windows 98, 2000 and XP regardless of some occasional blue screens.
I have noticed that sometimes Google Calendar view likes to change to mobile view in Opera that the only thing you can see is the weekly view in some plain HTML view.
In this case you want to go to this link to override it: https://www.google.com/calendar/render
If it happens that you cannot move the toolbox please use Atl + Mouse drag to resize it.
whatever you do or fix please test it afterwards, better however do not fix things that work, wait until they break otherwise feel the wrath of dummy users.