Visual studio 2013 "A task was cancelled"

I encountered the same error when I installed VS2013 update 5. During the installation my VS was open. Prior to installation of the update, I was asked to close VS but I neglected. That might have been the reason for the error although not sure about the exact cause.

After installation, the installer prompted me to restart the computer and the error was gone after I restarted my computer.

I am encountering similar problem with VS2015 update 3. Once this start happening I can't build application and can't start another instance Visual studio as it gives out of memory exception.

After looking through task lists I found out that there are many instance of conhost.exe and MSBuild.exe processes. So as temporary fix I kill all instances and try again building it is not perfect solution but works some times.

You can try run following batch commands.

Taskkill /IM MSBuild.exe /F
Taskkill /IM conhost.exe /F

Just to be complete,

Closing and reopening Visual Studio worked for me after I had changed the time zone and was getting the same errors as you.