IE 11 failed to create file object from byte array in Angular

Can anybody tell me why IE11 is throwing error In other browsers working only in IE getting error "object doesn't support this action"

let file = new File([files], newFileName, { type: Constants.FILECONTENTTYPE, lastModified: Date.now() });
                let uploadDocument = new UploadDocument();
                uploadDocument.fileName = newFileName;
                uploadDocument.fileItem = file;
                this.fileList = [];
                this.mergedFileList.forEach(fileItem => {
                    this.fileList.push(fileItem);
                });