I have Win 7 SP1. KStudio version 5.7.1 is installed. Was notified on KS launch that 5.8 available. Clicked on download (it showed completion). Click on Install/Restart… nothing happens. Checked Task Mgr - it showed ProductUpdater.exe *32 running, but not engaging any CPU cycles. There it sits… not completing the installation! 
Hi Phil Coulson,
I just updated successfully. Are you open two version Katalon at the same time? While you updating new version, you had opened another version, right?
In an open session this occurred, so yes.