Custom Date not working?

Has anyone else had issues with the SortItOutSI Custom Date editor file seemingly not working?

The game recognises it, and I've followed the instructions that are on the page, but when I come to try to use the custom date, the options are greyed out and can't be selected. Does anyone have any ideas?

Try not loading the MLS.

Yep, turns out the MLS breaks it. Cheers!

I don't believe it "breaks" it as such, it's just that the MLS is hard-coded (probably for licensing reasons) not to start any later than 2017. So if you want to start a save (even without this file) in 2018 in, say, Brazil, you cannot have the MLS loaded...