Php symfony 2&；sonata管理员调试工具栏损坏、失败，显示为空

有时我单击（symfony2&我使用sonata admin的后端）调试工具栏按钮，它显示为空白：

这是Firefox的源代码，它在这里被破坏（在svg标记中）：

你在你的应用程序日志中看到了这方面的信息吗？我已经看到了日志。但我没有发现任何问题。我找到了一些“request.INFO”和“event.DEBUG”日志，没有找到任何错误日志。
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