Is there a way for Tasker to notify me when a background app is using the voice recorder or the camera? Is there a way for Tasker to notify me when a background app is using the voice recorder or the camera?

I'm trying to find out which app is accessing the voice recorder in the background. Sometimes when I use the video recorder, I get a message saying the voice recorder is being used by another app.
Tasker cannot interact with background apps, and thus cannot detect if a background app is active or using the voice recorder. What Tasker can do, via Tasker Process Running (KC) is detect what processes, including apps, are running. if you store this data in some way whenever the error appears, you can look for correlations between running processes and the error. 

Note: Have you Googled around to see if your error is common with your device, app, or OS version?