Updated basically everything on the server (Ubuntu 16.06, PHP 7, and MediaWiki 1.28) this morning, though, and ran into a problem. Installed curl sudo apt-get install php-curl
and restarted the server; error remains the same.
[4f1546bd9c53f8d999378587] /index.php?title=KENDALL_C._GEDNEY,_LTJG,_USN&action=submit Error from line 357 of /var/www/html/extensions/SlackNotifications/SlackNotificationsCore.php: Call to undefined function curl_init()
Backtrace:
#0 /var/www/html/extensions/SlackNotifications/SlackNotificationsCore.php(135): SlackNotifications::push_slack_notify(string, string, User)
#1 /var/www/html/includes/Hooks.php(195): SlackNotifications::slack_article_saved(WikiPage, User, WikitextContent, string, integer, NULL, NULL, integer, Revision, Status, boolean)
#2 /var/www/html/includes/page/WikiPage.php(1912): Hooks::run(string, array)
#3 /var/www/html/includes/libs/rdbms/database/Database.php(2682): WikiPage->{closure}(DatabaseMysqli, string)
#4 /var/www/html/includes/deferred/AtomicSectionUpdate.php(33): Database->doAtomicSection(string, Closure)
#5 /var/www/html/includes/deferred/DeferredUpdates.php(263): AtomicSectionUpdate->doUpdate()
#6 /var/www/html/includes/deferred/DeferredUpdates.php(225): DeferredUpdates::runUpdate(AtomicSectionUpdate, LBFactorySimple, integer)
#7 /var/www/html/includes/deferred/DeferredUpdates.php(129): DeferredUpdates::execute(array, string, integer)
#8 /var/www/html/includes/MediaWiki.php(592): DeferredUpdates::doUpdates(string, integer)
#9 /var/www/html/includes/MediaWiki.php(561): MediaWiki::preOutputCommit(RequestContext, Closure)
#10 /var/www/html/includes/MediaWiki.php(867): MediaWiki->doPreOutputCommit(Closure)
#11 /var/www/html/includes/MediaWiki.php(512): MediaWiki->main()
#12 /var/www/html/index.php(43): MediaWiki->run()
#13 {main}