Uncaught TypeError: this.do_warn is not a function
    at Class._create_file (web.assets_backend.min.js:10281)
    at executeBound (web.assets_common.min.js:181)
    at Class.bound (web.assets_common.min.js:182)
    at FileReader.<anonymous> (web.assets_common.min.js:4851)

通过原码分析，需要更改下
this.do_warn(_t("You must select a directory first"));
        
this.displayNotification({ message: _.str.sprintf(
    _t("%d records successfully imported"),
    results.ids.length
) });