I suddenly got an internal error. On my Alerts say that "Failed to fetch notifications." and on the Special:Notifications page I'm getting the following error:
[2447d285182867a75232a839] /Special:Notifications InvalidArgumentException from line 13 of /var/www/html/extensions/Echo/includes/formatters/EchoIcon.php: The gratitude icon is not registered
Backtrace:
#0 /var/www/html/extensions/Echo/includes/formatters/SpecialNotificationsFormatter.php(110): EchoIcon::getUrl(string, string)
#1 /var/www/html/extensions/Echo/includes/formatters/SpecialNotificationsFormatter.php(18): SpecialNotificationsFormatter->getIconURL(EchoUserRelationshipPresentationModel)
#2 /var/www/html/extensions/Echo/includes/formatters/EchoEventFormatter.php(63): SpecialNotificationsFormatter->formatModel(EchoUserRelationshipPresentationModel)
#3 /var/www/html/extensions/Echo/includes/DataOutputFormatter.php(170): EchoEventFormatter->format(EchoEvent)
#4 /var/www/html/extensions/Echo/includes/DataOutputFormatter.php(136): EchoDataOutputFormatter::formatNotification(EchoEvent, User, string, Language)
#5 /var/www/html/extensions/Echo/includes/special/SpecialNotifications.php(59): EchoDataOutputFormatter::formatOutput(EchoNotification, string, User, Language)
#6 /var/www/html/includes/specialpage/SpecialPage.php(522): SpecialNotifications->execute(NULL)
#7 /var/www/html/includes/specialpage/SpecialPageFactory.php(576): SpecialPage->run(NULL)
#8 /var/www/html/includes/MediaWiki.php(283): SpecialPageFactory::executePath(Title, RequestContext)
#9 /var/www/html/includes/MediaWiki.php(851): MediaWiki->performRequest()
#10 /var/www/html/includes/MediaWiki.php(512): MediaWiki->main()
#11 /var/www/html/index.php(43): MediaWiki->run()
#12 {main}