又是一起因为忽略安装步骤导致的错误，先看画面

开启错误明细显示以及数据库错误反馈之后，大致明白跟我刚安装的echo扩展有关。
我们来看看说明中是怎么说的

• Download and place the file(s) in a directory called Echo in your extensions/ folder.
• Add the following code at the bottom of your LocalSettings.php:
  wfLoadExtension( 'Echo' );
• Run the update script which will automatically create the necessary database tables that this extension needs.
• If necessary configure at your convenience
• Yes Done - Navigate to Special:Version on your wiki to verify that the extension is successfully installed.

通常的扩展安装都是第一第二条就可以了，第四条的配置可以根据实际使用来确定，而最后一条则是告知你成功安装了！
漏了第三条，对吧！它的意思是啥？
运行更新脚本, 它将自动创建此扩展所需的必要数据库表。
更新脚本？那不是升级系统时候用的吗？
可事实就是，你运行更新脚本，然后问题解决了。看看终端返回的相关内容：

[root@iZ2362n1jwgZ maintenance]# php update.php
MediaWiki 1.30.0 Updater
Your composer.lock file is up to date with current dependencies!
Abort with control-c in the next five seconds (skip this countdown with --quick)
Creating echo_event table ...done.
...echo_email_batch table already exists.
...echo_target_page table already exists.
...event_agent field does not exist in echo_event table, skipping modify field p                                                                             atch.
Modifying event_variant field of table echo_event ...done.
Modifying event_extra field of table echo_event ...done.
Modifying event_agent_ip field of table echo_event ...done.
...have etp_id field in echo_target_page table.
...echo_target_page table does not contain etp_user field.
...have notification_bundle_base field in echo_notification table.
...echo_subscription doesn't exist.
...echo_event table does not contain event_timestamp field.
...have eeb_event_hash field in echo_email_batch table.
...have event_page_id field in echo_event table.
...index echo_event_type already set on echo_event table.
...index echo_user_timestamp already set on echo_notification table.
...index echo_notification_event already set on echo_notification table.
...have event_deleted field in echo_event table.
...index echo_notification_user_read_timestamp already set on echo_notification                                                                              table.
...index echo_target_page_page_event already set on echo_target_page table.
...index echo_event_page_id already set on echo_event table.
...user_event key doesn't exist.
...site_stats is populated...done.
...Update 'populate rev_len and ar_len' already logged as completed.
...Update 'populate rev_sha1' already logged as completed.
...img_sha1 column of image table already populated.
...protocol-relative URLs in externallinks table already fixed.
...fa_sha1 column of filearchive table already populated.
...*_from_namespace column of backlink tables already populated.
...Update 'FixDefaultJsonContentPages' already logged as completed.
...Update 'cleanup empty categories' already logged as completed.
...RFC and PMID already added to interwiki database table.
Populating page_props.pp_sortkey...
Updated 0 rows
Updated 0 rows
Populating page_props.pp_sortkey complete.
...Update 'populate ip_changes' already logged as completed.
Removing orphaned echo_event rows...
Purging caches...done.

Done in 0.9 s.

MediaWiki果真处处是玄机！