hmm, well I would guess all the animated battlers have the <Sideview Battler:name> tag not sure if you could do something with that.
As it turns out, all battlers, even non sideview ones have a number of parameters added to them whenever VS_BattleCore is enabled, and the name will be a blank string if the enemy doesn't have a battler set via that note tag.
I have used this, and it appears to work, at least in my quick testing, and it doesn't seem to cause the project to implode if the enemy is not an animated one, or if the VS_BattleCore isn't present in the project, so I consider that a win. The new version should be up in a few minutes, let me know if I missed something glaringly obvious on this one.
I've never seen that error before, not just for this file specifically, but in all of my time using windows. Perhaps the original file is corrupted somehow in your original location? Clearly after making the copy + paste action, the file pasted is also corrupted to throw that error.
Have you tried redownloading the plugin file and pasting that file instead? I don't think the js file has any weird file properties that would cause that error, unless some antivirus program has already been messing with it thinking that it's a malicious file or something.