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)：
unable to read cookie javascript
対処
関連リンク
unable to read cookie first time in javascript - Stack Overflowstackoverflow.com/.../unable-to-read-cookie-first-time-i...
https://stackoverflow.com/questions/12105346/unable-to-read-cookie-first-time-in-javascript
Javascript: Cookie can not be read in all the ...
https://stackoverflow.com/questions/17817227/javascript-cookie-can-not-be-read-in-all-the-html-pages・・・
Can't read cookie set by javascript in php
https://stackoverflow.com/questions/29097364/cant-read-cookie-set-by-javascript-in-php