There have been many case (in-)sensitivity bugs fixed in Regalia through the years. The version you included with the release in the OP is 0.9.8 which is years behind the current version, 0.9.21.
I have confirmed with
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that the 0.9.21 version can get through all the main content of the game, and the 0.9.8 version definitely cannot.
I'm sorry that you've had to spend time diagnosing issues with other peoples' code, but this is the same thing that happened
with the last release so it's a bit frustrating for me too.
I'm not sure how you made the Regalia release this time but
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the proper installation process (make sure to pull the latest code first!) but in a pinch it may be sufficient to just extract the updated version I posted on the last page.