无法理解原因，一周前一切正常，但在拨打wp-admin时突然发出以下警告信息显示空白屏幕无法输入登录详细信息和以下2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
在调用url作为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
我尝试在此警告中评论所有标题行，但仍无用。
感谢任何帮助。
答案 0 :(得分：1)
通常是因为在开始<?php标记之前或关闭?>标记之后有空格，新行或其他内容，通常在wp-config.php中。
这也可以在任何其他文件中。
检查您修改过的文件。显然，在你提到的最后一周内已经修改了一个或多个。