I've located the source of the trouble. The query to create the NCM_Nodes view has a problem. The query runs in SQL Studio but flags for the same issue as why the Database Manager errors and displays no output. I was able to fix the query for the View, but haven't implemented the changes in our DB until I hear back from SolarWinds Support. I created case 00404266 to track.
I'm not sure if they flipped some global setting that is causing the problem, hence may be causing trouble with other Views in the DB, or if they just happened to change this View query and it needs to be corrected.