I have the same problem here. iCUE is not opening for me.
I was using an older version of the iCUE without updating, when suddenly my reprogrammed keys stopped working. I had no choice but to update iCUE and then it updated to the latest version. And that's where I am now: iCUE is no longer opening. I tried uninstalling and reinstalling, restarting, but it still wouldn't work.
Also, opening LINK 4 and trying to launch iCUE didn't work for me. I only still see the LINK 4 window.
Should of restarted though...any ideas around this issue?