SONAR won't recognize my sound card as a valid output

I don't know why that is, because I've been using it for months and it's worked fine. Now when I go into MIDI Devices, I can still see it there under both Inputs and Outputs. However, when I go into the I/O for each separate track, there's nothing under Outputs.

Does anyone know why this might be happening? It seems like it should be easy to fix, if I knew where to look. Other applications like Windows Media Player work just fine, so I think it's just a problem with SONAR.