Starting the offline installer for the first time raises a warning from Windows Defender SmartScreen.

 
Microsoft Defender SmartScreen prevented an unrecognised app from starting. Running this app might put your PC at risk.
[More info|about:blank#]
 

You have to unfold "More info" - which basically contains no real details, but when doing so you'll get another button which allows to execute the Installer..

Note: former installers (before QC 4.14) did not raise this.. This seems also to apply for the 4.13.3 snapshot - so, has anything changed in the way we put the installer stuff together? Or is it even the installer itself?