First - nothing I said in that post was actually wrong. Simply not enough to solve their problem

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You do realize the same issue happens when extraction is fucked up (as in you extract only the first archive) and the game simply can't find the scene file because it's not there? We actually had that discussion last year and this year as well.
Been told a few times already.
1.) Check system locale if it is japanese.
2.) Switch languages ingame because it might be an issue (yes, English setting caused issues for this particular dialogue).
3.) If everything fails, check how you are unpacking the game from archives. It is not self extracting like usually but multiple separate files that each require extracting and merging manually (yes, game will launch if not fully extracted but it will freeze or crash at random places because it's missing files...obviously).
Me saying it was told a few times is not out of spite but to highlight it's not the first time someone had that issue and they can search the thread for few suggestions.
Second - thanks for posting this "further troubleshooting guide". I forgot you wrote it down point by point in 2023 already, saves explaining stuff to newcomers.
Why is your post still not pinned/linked in the first post when it's an issue that is brought up constantly by new people?

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Generally, full language package for Japanese OR traditional chinese (no need to set it up beyond the default text checking as it's only to make sure the system has the formatting schema at hand) and setting japanese locale in Windows10 should do the trick as I've just tested on virtual machine.