SWIFT 3 sucks! SUCKS I TELL YOU! swift 3 changes the NSError class to its own Error class, now the categories (i.e the extensions) that I have added to the NSError class (like convenience inits and NSDictionary map to my own variables) are ALL LOST !!! MORE THAN 100 LINES OF CODE LOST!! because of this piece of shit mutation of the DATA TYPE ITSELF!!! when objective C code is used in Swift (using the mix-match technique) DONT UPGRADE TO swift 3.0 GUYS DONT DO IT!!! especially if you have legacy code in your project !!