To test out the new error handling, just do something silly like removing a semicolon from one of the random map scripts, and then try loading it. You should be returned to the main menu with an error message, but more importantly, you should still be able to start a new game or anything else with no further problems.
Since Atlas doesn't support the new random maps yet, it's not a big deal if it doesn't handle errors yet. I guess eventually there should be a new message handler added so the engine can tell the Atlas UI to show an error.
