【code】里面不能添加at字符，否则论坛的数据库报错

今早 wayne 反馈如题的问题，报错如下：

Discuz! Database Error
(1146) Table 'emath.common_member_archive' doesn't exist
SELECT * FROM common_member_archive WHERE username IN ('@k[[All,1]],0},(k[[All,2]]/.List->Times)i[[2]]},{k,Tuples[Table[If[i[[1,ii]]+i[[1,ii+1]]==0,{{0,1}},{{0,(1-p)},{1,p}}],{ii,Length[i[[1]]]-1}]]}],{i,t}],1],#[[1]]&]}];')

PHP Debug
No.        File        Line        Code
1        forum.php        71        require(%s)
2        source/module/forum/forum_post.php        346        require_once(%s)
3        source/include/post/post_editpost.php        438        discuz_container->editpost(Array)
4        source/include/post/post_editpost.php        438        discuz_container->__call(%s, Array)
5        source/class/discuz/discuz_container.php        55        discuz_container->_call(%s, Array, %d)
6        source/class/discuz/discuz_container.php        84        extend_thread_allowat->before_editpost(Array)
7        source/class/extend/extend_thread_allowat.php        151        discuz_container->fetch_all_by_username(Array)
8        source/class/extend/extend_thread_allowat.php        151        discuz_container->__call(%s, Array)
9        source/class/discuz/discuz_container.php        59        table_common_member->fetch_all_by_username(Array)
10        source/class/table/table_common_member.php        78        discuz_container->fetch_all_by_username(Array, %d)
11        source/class/table/table_common_member.php        78        discuz_container->__call(%s, Array)
12        source/class/discuz/discuz_container.php        60        table_common_member->fetch_all_by_username(Array, %d)
13        source/class/table/table_common_member.php        76        discuz_database::fetch_all(%s, Array, %s)
14        source/class/discuz/discuz_database.php        100        discuz_database::query(%s, Array, false, false)
15        source/class/discuz/discuz_database.php        136        db_driver_mysql->query(%s, false, false)
16        source/class/db/db_driver_mysql.php        151        db_driver_mysql->halt(%s, %d, %s)
17        source/class/db/db_driver_mysql.php        218        break()
bbs.emath.ac.cn 已经将此出错信息详细记录, 由此给您带来的访问不便我们深感歉意. Need Help?

向论坛程序开发商反映，得到的答复居然是：请勿在后台点击用户表优化相关的设置。
之后，至后台更新缓存，一切就OK了。