[Hall of Famer]

First of all, Mys v1.3.3 is not yet available, it should be released within a week or two. On the other hand, each version comes with an upgrader, which can be used between minor releases so long as you have not heavily modified your script files. Between major releases though(like Mys v1.1.x to v1.2.x and v1.2.x to v1.3.x), you will need a mega-upgrader, for now its not available so Mys v1.2.x users are stuck with the old versions for now. The good thing is that, well as far as I know, there aint many people still running Mys v1.2.x, which is old and has too much spaghetti code to maintain.