After upgrading MediaWiki to 1.37 and to FlaggedRevs – (4dec80b) 14:21, 10 October 2021, I get the following error on the wiki, making it unusable:
```
Fatal error: Uncaught Error: Undefined constant "APCOND_FR_EDITSUMMARYCOUNT" in /var/www/vhosts/example.com/httpdocs/extensions/FlaggedRevs/FlaggedRevsSetup.php:55
Stack trace:
#0 /var/www/vhosts/example.com/httpdocs/extensions/FlaggedRevs/FlaggedRevsSetup.php(31): FlaggedRevsSetup->setAutopromoteConfig()
#1 /var/www/vhosts/example.com/httpdocs/extensions/FlaggedRevs/backend/FlaggedRevsHooks.php(68): FlaggedRevsSetup->doSetup()
#2 /var/www/vhosts/example.com/httpdocs/includes/HookContainer/HookContainer.php(338): FlaggedRevsHooks::onMediaWikiServices()
#3 /var/www/vhosts/example.com/httpdocs/includes/HookContainer/HookContainer.php(137): MediaWiki\HookContainer\HookContainer->callLegacyHook()
#4 /var/www/vhosts/example.com/httpdocs/includes/HookContainer/HookRunner.php(2517): MediaWiki\HookContainer\HookContainer->run()
#5 /var/www/vhosts/example.com/httpdocs/includes/MediaWikiServices.php(268): MediaWiki\HookContainer\HookRunner->onMediaWikiServices()
#6 /var/www/vhosts/example.com/httpdocs/extensions/BootstrapComponents/src/HookRegistry.php(381): MediaWiki\MediaWikiServices::getInstance()
#7 /var/www/vhosts/example.com/httpdocs/extensions/BootstrapComponents/src/HookRegistry.php(87): BootstrapComponents\HookRegistry->registerMyConfiguration()
#8 /var/www/vhosts/example.com/httpdocs/extensions/BootstrapComponents/src/BootstrapComponents.php(90): BootstrapComponents\HookRegistry->__construct()
#9 /var/www/vhosts/example.com/httpdocs/includes/registration/ExtensionRegistry.php(546): BootstrapComponents\BootstrapComponents::init()
#10 /var/www/vhosts/example.com/httpdocs/includes/registration/ExtensionRegistry.php(231): ExtensionRegistry->exportExtractedData()
#11 /var/www/vhosts/example.com/httpdocs/includes/Setup.php(168): ExtensionRegistry->loadFromQueue()
#12 /var/www/vhosts/example.com/httpdocs/includes/WebStart.php(90): require_once('...')
#13 /var/www/vhosts/example.com/httpdocs/index.php(44): require('...')
#14 {main} thrown in /var/www/vhosts/example.com/httpdocs/extensions/FlaggedRevs/FlaggedRevsSetup.php on line 55
```
If I comment my current configuration in LocalSettings.php out, downgrade to FlaggedRevs for 1.36 or downgrade my PHP to 7.4 the error goes away.
```
#$wgFlaggedRevsAutoconfirm = [
# 'days' => 15, # days since registration
# 'edits' => 25, # total edit count
# 'spacing' => 3, # spacing of edit intervals
# 'benchmarks' => 5, # how many edit intervals are needed?
# 'excludeLastDays' => 1, # exclude the last X days of edits from edit counts
# 'totalContentEdits' => 50, # $wgContentNamespaces edits OR...
# 'totalCheckedEdits' => 25, # ...Edits before the stable version of pages
# 'uniqueContentPages' => 5, # $wgContentNamespaces unique pages edited
# 'editComments' => 10, # how many edit comments used?
# 'email' => true, # user must be emailconfirmed?
# 'neverBlocked' => true, # Can users that were blocked be promoted?
#];
#$wgFlaggedRevsAutopromote = [
# 'days' => 30, # days since registration
# 'edits' => 50, # total edit count
# 'excludeLastDays' => 2, # exclude the last X days of edits from below edit counts
# 'benchmarks' => 10, # number of "spread out" edits
# 'spacing' => 3, # number of days between these edits (the "spread")
# 'totalContentEdits' => 100, # edits to pages in $wgContentNamespaces
# 'totalCheckedEdits' => 50, # edits before the stable version of pages
# 'uniqueContentPages' => 10, # unique pages in $wgContentNamespaces edited
# 'editComments' => 25, # number of manual edit summaries used
# 'userpageBytes' => 0, # size of userpage (use 0 to not require a userpage)
# 'neverBlocked' => true, # username was never blocked before?
# 'email' => true, # user must be emailconfirmed?
# 'maxRevertedEditRatio' => 0.03, # max fraction of edits reverted via "rollback"/"undo"
#];
```
MediaWiki 1.36 worked with this configuration, PHP 8 and the stable FlaggedRev for 1.36 that can currently be downloaded.