Helium not connecting to PC

[AC Question]

Hi. I'm trying to use Helium to backup my Samsung Galaxy S5 before doing a reset on the phone. I have installed the app on the phone and on the PC (Windows 7) as well as the driver Helium suggests in its opening window. And have connected them by USB cable of course. But the phone is stuck on "Waiting for the Helium Desktop application to enable application backup on your Android..."

The phone's OS is 5.1.1

Suggestions?