I did try to redownload it, but to no avail. Still got stuck at 41%
I did some digging in the gamefiles though, and as the log says, there is no function name show_error in either LoadScreen.gd or the Node class it extends. It seems the codeblock that throws the error is a copy/paste job gone wrong from the Godot Wiki, where show_error is included as a placeholder function.
I don't know GDScript very well though, so I'm not certain this is the case, nor how error handling should be done, and either way, this is most likely only related to actually showing the error, not fixing the cause of it.
Commenting out show_error gave me this log instead: https://pastebin.com/zLVmDrWH
I don't know what went wrong when loading the resources (And I'm not quite sure how to debug it, as I'm not familiar with godot), but interactionpanel.tscn definitely is present in my game directory, even though rope.png isn't.
Looking at the files in /files/buttons/sexicons there are no .png files at all, only *.png.import, which specify how to import the resources, but not the actual pictures themselves. Is it possibly related to this?