reactjs error - AJAX Failed: SyntaxError: Unexpected token < in JSON at position 0

reactjs error - AJAX Failed: SyntaxError: Unexpected token < in JSON at position 0

我在 运行 reactjs 应用程序的控制台上收到以下错误。

   AJAX Failed: SyntaxError: Unexpected token < in JSON at position 0

在开发者工具控制台上 window。我收到以下错误。

 search-e3e9d0f9da88f042e3cb.js:446 Warning: React attempted to reuse markup in a container but the checksum was invalid. This generally means that you are using server rendering and the markup generated on the server was not what the client was expecting. React injected new markup to compensate which works but you have lost many of the benefits of server rendering. 
 Instead, figure out why the markup being generated is different on the 
 client or server:
 (client) " data-reactid="18">Medium</div><button 
 (server) " data-reactid="18">Large</div><button s

是wagtail应用(类似Django-cms),在wagtail应用内部调用了react模块。开发环境是aws上的Ubuntu。

请帮我解决这个问题。我找不到错误的来源。

看来你的JSON无效,试试jsonlint.com