All update notes apply to the whole scenario.
As for being unable to change the difficulty settings please see the GitHub. That's a known game bug and the workarounds are also posted there.

Yeah, "easy mode" was a rather sarcastic response to a vocal minority of people who like to whine about the "difficulty" of RE2 and its shield penetration mechanic.

But, I wanted to say that I feel you. I severely broke both my arms in a car accident when I was a kid. (It was before seat belts were mandatory equipment in cars -- Yes, I'm that old -- and I tried to stop my forward motion using both my arms against the dashboard. Bad idea, but it was reflex, so...) I damn near lost my left arm below the elbow, but both were saved. I do, however, have nerve damage that makes especially my left hand very weak and clumsy. My right hand is better, but still weaker and clumsier than normal, so I have difficulty with quickly manipulating a mouse, and thus am pretty bad at games involving first-person shooting and mostly avoid them. But, I enjoy EGS, and I muddle through. For this reason, I usually play with easy enemy difficulty, so it doesn't take as much effort to kill the baddies, but I am currently trying out medium enemy difficulty (the default) with a Sienna start and I'm doing all right-ish. LOL I die a lot, but I also have things set so that I don't lose any stuff when I die, so it's not too bad.

I have never tried the Purgatory start, but I have done some of the harder ones and was able to start the game with easy enemy difficulty set. I'm now curious to see if I could start the Purgatory one because of all the really hard ones, that one is the one that interests me the most. I'm glad there are work-arounds if I have the same problem.

Yeah it's just annoying that the bug is unlikely to be fixed anytime soon. So check GitHub for the known work arounds.
When or if they fix the bug it'll be updated there.

Also when you go to start a new game the work around is also shown right there in the scenario description.

Thanks ravien, but maybe they've fixed the bug? I didn't go to GitHub, didn't even know about it (yeah, I'm that clueless), but for grins I went into the scenario, checked off my difficulty changes, and it started just fine. I'm now living in the Engine Compartment and have an ugly little SV built. I tend to really enjoy the almost frantic survival aspects of the very early part of the game. Going beyond that and picking fights isn't my strong suit.

Will it start back up tomorrow? I'll find out. But thanks again for your help. Now you get back to work on the game, things like being able to use the detector with your laser drills and weapons retracted.

引用自 rick813：

Thanks ravien, but maybe they've fixed the bug? I didn't go to GitHub, didn't even know about it (yeah, I'm that clueless), but for grins I went into the scenario, checked off my difficulty changes, and it started just fine. I'm now living in the Engine Compartment and have an ugly little SV built. I tend to really enjoy the almost frantic survival aspects of the very early part of the game. Going beyond that and picking fights isn't my strong suit.

Will it start back up tomorrow? I'll find out. But thanks again for your help. Now you get back to work on the game, things like being able to use the detector with your laser drills and weapons retracted.

No, the bug is not fixed, and you very well may have caused a broken save by starting the scenario without using one of the workarounds after changing difficulty settings.