I just had this happen to me, but both first and last names have been changed to Smith.
Playing a historical league starting in 1901. I just finished the 1917 season earlier tonight and the game automatically imported the draft class as normal. I run the draft and sim until February-whatever when the game switches to the next season statistically, then exit the game. Come back a few hours later, start the game up, sim until Spring Training and start looking at my roster. All of a sudden guys are named Smith (it may have happened when the year switched, or even after the draft before then, but I wasn't paying attention). Chief Bender became Smith Bender. Smokey Joe Wood became Smith Wood. Nemo Leibold became Nemo Smith, so on and so forth.
It just completely killed a league I had put a lot of time into. I rarely take a league past 10 years and this one was going strong.
