今天在论坛的后台进行操作，在点击论坛功能部分后，就出现了error信息。
[phpBB Debug] PHP Notice: in file /includes/acp/acp_board.php on line 877: Undefined index: ALLOW_QUICK_REPLY_BUTTON
[phpBB Debug] PHP Notice: in file /adm/index.php on line 151: Cannot modify header information - headers already sent by (output started at /includes/functions.php:3493)
[phpBB Debug] PHP Notice: in file /adm/index.php on line 153: Cannot modify header information - headers already sent by (output started at /includes/functions.php:3493)
[phpBB Debug] PHP Notice: in file /adm/index.php on line 154: Cannot modify header information - headers already sent by (output started at /includes/functions.php:3493)
[phpBB Debug] PHP Notice: in file /adm/index.php on line 155: Cannot modify header information - headers already sent by (output started at /includes/functions.php:3493)
Google了一下，自己也琢磨了一下，估计是部分词条没有定义，造成ALLOW_QUICK_REPLY_BUTTON没有定义。
因为使用了中文语言包，同原版的可能会有不同，就分别打开了
language / en / acp / board.php
和
language / zh_cmn_hans / acp / board.php
的确发现中文下面少了这条，在大约第77行。
'ALLOW_QUICK_REPLY_BUTTON' => 'Submit and enable quick reply in all forums',
添加好后，就没有问题了。
这应该是系统升级到3.0.7-PL1时引入的。
