The "no implicit conversion from nil to integer" seems to be caused by the game trying to pass Nil off as an Actors ID...
Probably something
Towerfag will need to look into as it's outside the Patch System since it deals with Internal Scripts.
You could use
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to extract Game.rgss3a then replace 'Data\Scripts.rvdata2'
https://f95zone.to/threads/princess-conquest-v0-17-11-towerfag.602/post-4290040
Though I only tested that fix against Dragon Princess I and II.
As for audible errors eh not sure though I have seen others have issues Saving/Loading while on the World Map before.