Make sure you selected the windows version of eggnoggplus.exe, and it should just work? Do you get to the level selection screen in the map editor or is it just a completely blank level?
i can see all the levels and i can also edit. but when I press the save or save and play button nothing happen and yes i am selecting the windows version
Does literally nothing happen or does the app give an error on the screen? Maybe it's a windows 11 issue, try launching i in administrator mode. Also, are you sure the game is closed and that it is not being used by any other map when you're trying to save?