I keep getting an error on RedLaser app for iPod Touch 4th generation. How to fix?
kCLErrorDomain is error reporting regarding the OS framework "Core Location." See this document for more info (written for OS X, which iOS is based upon).

So, for troubleshooting, I'd check your location services, maybe disable them/re-enable them and relaunch the app.  

If that doesn't work, try re-downloading the app.

If the issue persists after a reinstallation of the app, the next step I would try would be to restore your device.