[Area] Exceptions [Syntax rule] Now you can throw and catch only int values It was possible to throw scalar expressions like strings and dates, such as throw "hello world";, and get no compile error. At runtime this was catch-able by a catch block that was not decorated with any specific value, such as catch {print("Catch worked.");}.
Now the only expression you can put on the throw keyword is an int. Often the best thing to throw is Global::error("Explanation");. Often the best thing to catch is an element of the Exception enum. For more information, see Exception Handling with try and catch Keywords.