Yes. Same thing happens. When I push or hold the F1 key, the game window disappears and I am back at the desktop. Then I hear the "Trainer Activated" voice. The funny part is is that there's no game running!
Crytek played this one beautifully.

Update:

I overlooked a previous post suggesting to hit the F1 key almost immediately after double-clicking the Crysis 3 icon (After starting up the trainer first). This worked!! I loaded up my saved game, then hit numpad 2 for the unlimited energy. Then I enabled cloaking and the voice said "trainer activated" and the energy bar never depleted. Didn't try the other options yet, though. Thank you.

[Edited by scoobots, 3/3/2013 1:37:53 AM]

I play hunter edition, got from origin and updated. I put the trainer in the same folder as Crysis3.exe (C:\Program Files (x86)\Origin Games\Crysis 3\Bin32). Both Crysis3.exe and trainer run in administrator mode using shortcuts created on desktop (trainer first, game, F1 and so on).

however I seem to have the immortal Alpha at the end so I've had to put the game back to normal and will have to complete this bit without cheats.

[Edited by merseymal, 3/3/2013 9:39:13 AM]

A few days ago I reported that the trainer's nano upgrade feature didn't work for me. It turns out that the instruction file that I printed out (may have been the previous version of the trainer) stated that the F5 key press gives 99 nano upgrade points. The current 1.0.0.2000 version of the trainer indicates right on the menu that it is the F4 key performs that function. It WORKS!

but the mega ammo seems to work only for the bow

my pistol and other guns remain with normal ammo when i press this