This was an error that's fixed in the EP3v1.03 patch available on Patreon. You may have downloaded the game from somewhere else as it's not updated.
Alternatively, if you back up before the error occurs >> go into the game options >> unselect "Show Unavailable In-Game Choices". This should be a workaround to avoid the error. After you pass the error point, you may turn that option back on if you wish.