i literally have no idea what im doing

I play on Mac, and I'm trying to go back a day. I did the thing where you trash the SaveGameInfo folder, and rename the SaveGameInfo_old to SaveGameInfo, and in the farm load screen, looked like it worked. It displayed the say before, Spring 18, but when I entered the save, it was Spring 19...

I use the latest Smapi version for Android, and everytime I try to load my save file, it opens to the loading screen, and then the music cuts out and it lingers there until I'm told the app encountered a problem. I have a few mods installed, but they all run fine, and nothing of note seems to...