GameMaker: Studio is a pretty big hassle, unless you like porting code over that is obsolete in Studio. I'm looking at a solution to make Studio viable for many I wanna makers but its just not possible right now because Studio is made for Mobile games or games in a Sandbox environment which can cause many problems with Saving and Loading in most Modern I wanna engines. I recommend to continue using GM8.1, you can ask Sephalos on the forum, he has a tool that will allow you to use the GameMaker without any problems.