I think something may be corrupt with your game. Try re-downloading (you can carry over your saves without issue). I can't reproduce the issue on my end: swapping out the gallery file still allows movement up and down with the arrow keys in the gallery. Also, just to cover bases, remember this is Windows only. Some of the things I do with various plugins WILL break the game on Linux, Mac and Mobile.
Viewing post in Bug Reports Thread - Version 1.0.x (Content Pack 3)
Hmm, I have already tried downloading the game again, with a brand-new save, yet it wasn't capable of fixing the error itself. Might just be a problem on my end then, would be a shame if the gallery didn't work at all though. I'll see if it maybe works on a normal run eventually. Oh and, I am on Windows, so I don't think it's a problem with the plugins themselves, but I can't see what it could be.
Very strange. It's definitely something specific to you, as I'm sure I would be getting a LOT of complaints if the gallery unlock totally broke the gallery for everyone. I just wish I could be more helpful. So to be clear, on a fresh install without using the unlock, can you move up and down in the gallery? You'll only see static, but there will be an audio cue and shifting static to show you're moving from one entry to the next. In other words, I wonder if the gallery just isn't working period for you for some reason. All the gallery unlock does is swap some "0"s for "1"s in an index; that shouldn't be CAPABLE of breaking anything other than what scenes you can play.
Well, after testing it out I have found out that the problem wasn't with the gallery itself, but one of my inputs just wasn't working properly. I had to swap keyboards and now it seems to be functioning properly. Turns out the problem was indeed on my end, so I am so, so sorry that I wasted your time with this- Should've been more thorough on my testing. Thank you for your attention and once again, really sorry!