PLZ HELP HAVING A PROBLEM WITH SMAPI

[Plzhelpmesdv15version]

So I'm trying to get some mods for my girlfriend on sdv but I've ran into a roadblock. I ended up getting a 1.5 version of stardew valley off of pdalife and it was modded and I didnt want it but it was the only one that worked I got the 1.5 version of SMAPI and i keep getting "attempt to invoke interface method 'int java.lang.comparable.compareTo(java.lang.Object) on a null object reference" I don't know what to do im stuck if i could any help that would be amazing.