Can I get rid of this error?

I ran the script and it returns "an Illustrator error occured: 1128549443 ('CDLC')". Admittedly I'm not sure where to reference what that means, but I think it probably has to do with either your index number in the loop (if i = 1, then your use of i - 2 returns a value of negative 1) or use of activeDocument.artboards (instead of app.activeDocument.artboards or myDoc.artboards). I tested this with no errors returning:

var myDoc = app.documents[0];
var myABs = myDoc.artboards.length - 1;
for (var i = myABs; i > 0; i--) {
  myDoc.artboards.setActiveArtboardIndex(i)  
  myDoc.artboards.remove();
}

You could also use try and catch statements like so:

// attempt to execute code in a try{ ... } block
try {
  for (var i = myABs; i > 0; i--) {
    myDoc.artboards.setActiveArtboardIndex(i)  
    myDoc.artboards.remove();
  }
} catch(error){
  // catch statement is only in effect if an error occurs:
  alert(error);
  // if you wanted to bypass an error purposefully, you could use throw or something like:
  // } catch(e){return}
};