Here's what I did: I have a multi-part Windows 10-account like "John Doe". Qlik Sense 3.0 doesn't start (it gives a blank screen). When I installed Qlik Sense from another Windows 10 account, on the same laptop, like "John", Qlik Sense worked immediately.
I had a similar problem. When I tried to open C:\Users\<UserName>\AppData\Local\Programs\Qlik\Sense\QlikSenseBrowser\QlikSenseBrowser.exe it did not work. I was able to open Qlik Sense 3.0 from C:\Users\<username>\AppData\Local\Programs\Qlik\Sense\QlikSense.exe though. Does that work for you?