SAP: If Where-used fails or you want to find a message - use ABAP Code Scanner
In my previous post I complained about people not using the message statement to output error messages. But sometimes Where-used does indeed fail because it is not up-to-date.
A little known transaction (at least I hardly read about it) comes to help: CODE_SCANNER.
It allows you to input a package and a search string and will find you all lines of code that contain that string.