I switched from Windows 10 back to Windows 7.   And I changed my interface from the Scarlett 2i4 to the Behringer UMC404HD.   When I played a song, the meters were moving, but there was no sound.
 
I always keep the speaker icon in the bottom right turned off.   But I turned it on to see if that was the issue - and it was.    I don't know why the computer speaker is working for my monitors.   It never used to.   
 
And I right clicked the speaker icon to make sure the Playback and Recording devices were on the Behringer interface.   I don't want the computer speaker to work for the volume for my monitors.   How do I change it?
 
Greg

Did you install the ASIO driver?
 
 https://www.musictri.be/C...04HD/p/P0BK1/downloads

Check Control Panel/Sound/Playback and make sure your onboard sound is assigned to Speakers. This should reset your sound in SONAR to your Behringer. And make sure you have ASIO drivers installed like Johnny said. :)

Cactus Music:  Yes, ASIO drivers are installed.
 
Phoen1XPJ:  I will check Control Panel.
 
Thanks!
Greg

"I always keep the speaker icon in the bottom right turned off.   But I turned it on to see if that was the issue - and it was.    I don't know why the computer speaker is working for my monitors.   It never used to.  "  
 
I didn't read this correctly the first time.  I am pretty sure the speaker icon is for what ever audio device is set as default ( Green check)  in the mixer control panel.  I don't have an audio interface here with me right now to test, But I do know for sure I have never muted the speaker icon ever.  
When you use your ASIO interface it should be your only sound source. Some people can use the on board sound in parallel but often it is best to disable the on board and the HDMI audio and only use your interface and ASIO.  
 

Thanks, Cactus.   Everything was set as it should be, but the main speaker icon was controlling the sound, for whatever reason.  So I took out the Behringer and put the Focusrite back in, and now it works right.  Not sure why the Behringer did that.
 
And I will try your suggestion about disabling the on board sound and HDMI audio.
 
Thanks!
Greg