Works fine for me and two others. This is with persistent removal, too. This isn't your typical gallery unlocker, it actually dynamically unlocks it all using Ren'Py's own backend for Replays, marking the labels as seen (as in, experienced). The rest of the gallery is controlled by variables, and they're also dynamically calculated and unlocked, automatically with any/all new versions. Shit attitude, btw.
Edit: Tested *AGAIN*, works perfectly fine. Completely cleaned Ren'Py persistent and local, something is wrong with your end. You're missing files or your storage is dying. (Or you copied a new install over an old install, never do that.)
Edit: Below someone points out that the Remake hasn't implemented the gallery. You do realize the mod can only work for the versions with an implemented gallery?