I'm having some issues as well so far, though I haven't really done much testing yet. After updating my game and the trainer, I was able to get back into the game, and immediately pull up the menu and start enabling all the fun stuff, and an autosave pops up, which ended up making the trainer menu disappear, and was unable to get it to come back again. After restarting the game, it started crashing back to the desktop, exactly like it was before updating to 1.12. I figured reinstalling the trainer would be worth a shot, and it worked. Before trashing all the files, I did notice the same 7E945C8 thing mentioned earlier.
Now, I'm playing the game, but the unlimited items option is not working.
Also tried F11 teleport, stopped the trainer.
Will edit if I find anything else