Hopefully, the problem has been solved. The problem was because of my pc's calendar. If the pc's calendar would be as another language (other than English), Minecraft won't identify it in java 16 and then crashes the game. This problem isn't present when you open minecraft's older versions which would be launched on java 8 or older.
I think you have to add a code in the next snapshot which identifies the calendar, even with other languages. Because there are MANY people who don't know about this.
Avoma I don't think it's a duplicate. The issue that you linked is just for the moment you hold the breeding item; not in general. And since iron golems and creepers are non-breedable, that doesn't make sense.