[LayaAir 1.0]Invalid character: '`' Stack:[native code]异常

在真机上偶发出现Invalid character: '`' Stack:[native code]这个异常
SyntaxError
line:12852,column:0,SyntaxError: Invalid character: '`' Stack:[native code]
evaluateScriptFile@https://lib/WAGame.js:1:83259
value@https://lib/WAGame.js:1:178231
value@https://lib/WAGame.js:1:177377
https://lib/WAGame.js:1:182272
_@https://lib/WAGame.js:1:179659
https://lib/WAGame.js:1:182186
u@https://lib/WAGame.js:1:2543
N@https://lib/WAGame.js:1:182108
https://lib/WAGame.js:1:604466
global code@https://lib/WAGame.js:1:604471 
 
找了下引擎的源代码，发行在laya.core.js第12850行有2个`符号，不知道是不是这个引起的异常？
if (!this._data){
                    this._data=data;
                    if (data.meta && data.meta.image){
                        var toloadPics=data.meta.image.split(",");
                        var split=this._url.indexOf("/")>=0 ? "/" :"\\";
                        var idx=this._url.lastIndexOf(split);
                        var folderPath=idx >=0 ? this._url.substr(0,idx+1):"";
                        for (var i=0,len=toloadPics.length;i < len;i++){
                            toloadPics[i]=folderPath+toloadPics[i];
                        }
                        }else {
                        toloadPics=[this._url.replace(".json",".png")];``//这里出现特殊符号
                    }
                    toloadPics.reverse();
                    data.toLoads=toloadPics;
                    data.pics=[];
                }
                this.event(/*laya.events.Event.PROGRESS*/"progress",0.3+1 / toloadPics.length *0.6);
                return this._loadImage(toloadPics.pop());