THIS WORKS: (IT IS AN EASY WORK AROUND IF YOU TRY TO INSTALL WW2 WHILE YOUR GAME IS AT VERSION 1.21)

So, if you have installed the 1.2, and 1.21 incremental patch already, THEN installed the Battlefield WW2 Mod, do the following steps below to reinstall the patches, without having to reinstall the whole game.

What we are going to do is change the version number the game thinks it is, so you can apply the 1.2 and 1.21 patch.