I am running Windows 10 64-bit with Sonar Platinum. I have a single audio track fed from an instrument input on the Focusrite Scarlett 2i2 second generation. The output is fed to a set of TASCAM VL-S3 powered monitors, though I think this is irrelevant.
 
The output from the right monitor is very low, but it I do hear slightly if I pan hard right within the track in Sonar.
 
I think the problem is either I am using the 2i2 interface incorrectly or something inside Sonar. I can see from the input meter of the audio track in Sonar that the right input appears to be coming in low.
 
Anyone have experience with the Scarlett 2i2 who might be able to help me out?

Looks like you have the input in Sonar set to stereo, but it should be only a single channel (Left for the 1st input and Right for the second). Just set the input in Sonar correctly.

Thank you very much - that was the case.