When rolling wmf.16 out onto test wikis this appeared in logstash.
The exception is not user facing, but would likely result in mentions / mention notifications failing.
You can easily reproduce with an edit such as: https://test.wikipedia.org/w/index.php?title=Wikipedia_talk:Foo&oldid=341564
```
[WlUvtQpAMEMAACjJwl8AAADM] /w/api.php MediaWiki\Storage\RevisionAccessException from line 217 of /srv/mediawiki/php-1.31.0-wmf.16/includes/Storage/RevisionStore.php: Could not determine title for page ID 182836 and revision ID 303638
```
```
#0 /srv/mediawiki/php-1.31.0-wmf.16/includes/Storage/RevisionStore.php(1714): MediaWiki\Storage\RevisionStore->getTitle(integer, integer)
#1 /srv/mediawiki/php-1.31.0-wmf.16/includes/Revision.php(926): MediaWiki\Storage\RevisionStore->getPreviousRevision(MediaWiki\Storage\RevisionStoreRecord)
#2 /srv/mediawiki/php-1.31.0-wmf.16/extensions/Echo/includes/DiscussionParser.php(24): Revision->getPrevious()
#3 /srv/mediawiki/php-1.31.0-wmf.16/extensions/Echo/Hooks.php(553): EchoDiscussionParser::generateEventsForRevision(Revision)
#4 /srv/mediawiki/php-1.31.0-wmf.16/includes/deferred/MWCallableUpdate.php(30): Closure$EchoHooks::onPageContentSaveComplete()
#5 /srv/mediawiki/php-1.31.0-wmf.16/includes/deferred/DeferredUpdates.php(259): MWCallableUpdate->doUpdate()
#6 /srv/mediawiki/php-1.31.0-wmf.16/includes/deferred/DeferredUpdates.php(210): DeferredUpdates::runUpdate(MWCallableUpdate, Wikimedia\Rdbms\LBFactoryMulti, string, integer)
#7 /srv/mediawiki/php-1.31.0-wmf.16/includes/deferred/DeferredUpdates.php(131): DeferredUpdates::execute(array, string, integer)
#8 /srv/mediawiki/php-1.31.0-wmf.16/includes/MediaWiki.php(900): DeferredUpdates::doUpdates(string)
#9 /srv/mediawiki/php-1.31.0-wmf.16/includes/MediaWiki.php(720): MediaWiki->restInPeace(string, boolean)
#10 [internal function]: Closure$MediaWiki::doPostOutputShutdown()
#11 {main}
```