When I selected the item for doing the vaccine in the key card room of the laboratory, the cutscene just freezed and game wasn't answer, I could only reset, anyone know how to solve this?

I found an unofficial patch that can solve this problem:

UNOFFICIAL RE2 Door & Cutscene Skip mod patch file - Resident Evil 2 - ModDB

happened to me once. I don't remember exactly what I did to fix it, but I no longer held down the run button during the cutscene. I think this patch is also a good choice.

I'm the author of the unofficial patch. Nobody asked, but I can explain the cause of this bug, because I think it's kind of funny and interesting. This bug happens in the unpatched cutscene skip mod if the second (inner) sliding door is closing at the same time you start the cutscene, which can only happen if one of the zombies triggers it while you're on the way to the machine. Basically, the game has a bunch of "scripts" in each room which manage things happening in that room, and it has a certain number of "slots" that scripts can run in when multiple scripts need to be running at once. When the vanilla game starts the cutscene script, it doesn't specify a specific slot for it to run in, it just says "run this cutscene script in whatever the next free slot is." But the CSS mod author needed it to run in a known slot, so that when you press the button to skip the cutscene, his code could tell the game to stop the script in that slot. So he changed it to run in a specific slot, but he accidentally picked the same slot used by the script that handles opening the sliding door. And it turns out that, as a failsafe, the door closing script has code to stop the opening script if it's running, to make sure the game never tries to open and close the door at the same time. So if you activate the machine while the door is closing, the mod starts the cutscene script in the slot that's supposed to handle opening the door, and the closing script instantly stops it because it thinks the door is trying to open when it's supposed to be closing, and that stops the cutscene without ever running the code to unpause the game, so you're just stuck forever. The unofficial patch fixes this by moving the cutscene to a different slot that's not used by anything else.