Php 已通过WordPress仪表板中的警告发送标题

无法理解原因，一周前一切正常，但在呼叫wp admin时，突然出现以下警告消息，显示一个空白屏幕，无法输入登录详细信息和以下两条消息

Warning: Cannot modify header information - headers already sent by (output started at /home/username/public_html/wp-content/plugins/js_composer/composer/lib/composer.php:1) in /home/username/public_html/wp-includes/pluggable.php on line 896

当我尝试调用wp-login.php时，会出现以下错误消息

Warning: Cannot modify header information - headers already sent by (output started at /home/username/public_html/wp-content/plugins/js_composer/composer/lib/composer.php:1) in /home/username/public_html/wp-login.php on line 415

Warning: Cannot modify header information - headers already sent by (output started at /home/username/public_html/wp-content/plugins/js_composer/composer/lib/composer.php:1) in /home/username/public_html/wp-login.php on line 427

当调用url为wp-login.php时，会显示登录屏幕，但在输入登录详细信息后，会显示以下警告消息

Warning: Cannot modify header information - headers already sent by (output started at /home/username/public_html/wp-content/plugins/js_composer/composer/lib/composer.php:1) in /home/username/public_html/wp-login.php on line 415

Warning: Cannot modify header information - headers already sent by (output started at /home/username/public_html/wp-content/plugins/js_composer/composer/lib/composer.php:1) in /home/username/public_html/wp-login.php on line 427

Warning: Cannot modify header information - headers already sent by (output started at /home/username/public_html/wp-content/plugins/js_composer/composer/lib/composer.php:1) in /home/username/public_html/wp-includes/pluggable.php on line 678

Warning: Cannot modify header information - headers already sent by (output started at /home/username/public_html/wp-content/plugins/js_composer/composer/lib/composer.php:1) in /home/username/public_html/wp-includes/pluggable.php on line 679

Warning: Cannot modify header information - headers already sent by (output started at /home/username/public_html/wp-content/plugins/js_composer/composer/lib/composer.php:1) in /home/username/public_html/wp-includes/pluggable.php on line 680

Warning: Cannot modify header information - headers already sent by (output started at /home/username/public_html/wp-content/plugins/js_composer/composer/lib/composer.php:1) in /home/username/public_html/wp-includes/pluggable.php on line 896

我试着在这个警告中注释所有标题行，但仍然没有用

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感谢您的帮助。

这通常是因为在打开

标记之前有空格、新行或其他内容，通常在wp-config.php中

这也可能存在于任何其他文件中

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检查已修改的文件。显然，在您提到的最后一周内，一个或多个已被修改

从警告中可以看出，在/home/username/public_html/wp content/plugins/js_composer/composer/lib/composer.phpSimply中有空格，您可以使用函数ob_start（）；简单地说，您可以使用函数ob_start（）；之后