このエラーメッセージに関する原因と対処に関して説明します。
エラーメッセージ(英語)：
javascript' is not a member of
対処
関連リンク
routesImport: object _ is not a member of package _ ・ Issue ...github.com/playframework/playframework/issues/3470
https://github.com/playframework/playframework/issues/3470
Need Javascript to validate one required field | The ASP.NET Forumsforums.asp.net/t/1583471.aspx?Need+Javascript...
https://forums.asp.net/t/1583471.aspx?Need+Javascript+to+validate+one+required+field
JavaScript "javascript' is not a member of"のヤフオク!検索結果（357件）ヤフオク!
https://auctions.yahoo.co.jp/search/search?rkf=2&p=JavaScript+%22javascript%27+is+not+a+member+of%22・・・