Recently installed newly released Avast Internet Security 11.1.2241 on Windows 10 powered HP notebook. Worked great until I hibernated my notebook. After resuming few hours later, Windows 10 loaded but Start and Taskbar stopped working. I had to force shutdown notebook and restart it to fix the problem. Shutdown also got stuck at the end. This happened several times after which I ended up uninstalling this lousy product. Later I installed Avast Premier trial just for testing and to my surprise that also caused the same problem. So, fix it ASAP and make sure developers are not drunk while releasing a new product. >:(
What other security software do you have now or ever had?
If uninstalled how was it removed?
Through the Control Panel or the vendor?
Check my signature below to see what security software I have installed.
None other. This was the first antivirus installed on brand new machine.
(Besides that CAPTCHA verification totally sucks for newbie users. So much for antivirus developer’s forums which could not employ a better hassle free spam detection mechanism.) 
Take a look HERE at this topic, you’ll notice that in the link posted in my reply in that topic that Avast is aware of "a known “bug” involving the C++ Boost library that is expected to be fixed with the next Boost release that has been causing unwanted behavior in certain waits/timers. ", which may also be related to your issue as well.