Altering AoE2: Definitive Edition - Altering Userdata Units w/o crashing

On my old AoE2: TC / HD edition, myself and my buddy could alter the user data files with Genie and change some of the units to make the game a little more difficult - for us. I'd send him the altered empires2*.dat files and life is good. However, the network engine simulation has quite a few bugs (lag), whereas the new engine does not.

Now, when I try and do the same thing on the AoE2: DE (with a sample mod), the game crashes with "Can't create world" no matter what we try. I tried the Genie editor that comes with AOE2: DE

Has anything had success doing this without it crashing? Any guides?

The tl;dr - I cannot edit units in the userdata files with a sample mod. It crashes.