I wrote "PI" in a driver expression, and Blender threw up this warning message. I don't understand why it thinks there's a problem, nor what implications any of the choices have.
What is the security issue with using PI in a driver expression? What "unexpected behavior" is it talking about? If I choose "Ignore", will my driver stop working? If I choose "Allow Execution", am I inadvertently allowing other scripts I'm unaware of to run? And what does "Permanently allow execution of scripts" mean, is it saying any python scripts in any blender file can run henceforth, or what?