Noticed this error when viewing Special:RecentChanges on a 1.26.2 test wiki (the db was still not upgraded to 1.26 from 1.25 yet):
```
[8db7d018] /wiki/Special:RecentChanges Flow\Exception\FlowException from line 159 of /srv/mediawiki/w/extensions/Flow/includes/Formatter/ChangesListQuery.php: Revision not found in revisionCache: sv3f6bved6h0kihe
Backtrace:
#0 /srv/mediawiki/w/extensions/Flow/Hooks.php(506): Flow\Formatter\ChangesListQuery->getResult(EnhancedChangesList, RCCacheEntry, boolean)
#1 /srv/mediawiki/w/extensions/Flow/Hooks.php(490): FlowHooks::onEnhancedChangesListModifyBlockLineData(EnhancedChangesList, array, RCCacheEntry)
#2 /srv/mediawiki/w/includes/Hooks.php(201): FlowHooks::onEnhancedChangesListModifyLineData(EnhancedChangesList, array, array, RCCacheEntry)
#3 /srv/mediawiki/w/includes/changes/EnhancedChangesList.php(419): Hooks::run(string, array)
#4 /srv/mediawiki/w/includes/changes/EnhancedChangesList.php(276): EnhancedChangesList->getLineData(array, RCCacheEntry, array)
#5 /srv/mediawiki/w/includes/changes/EnhancedChangesList.php(683): EnhancedChangesList->recentChangesBlockGroup(array)
#6 /srv/mediawiki/w/includes/changes/EnhancedChangesList.php(103): EnhancedChangesList->recentChangesBlock()
#7 /srv/mediawiki/w/includes/specials/SpecialRecentchanges.php(356): EnhancedChangesList->recentChangesLine(RecentChange, boolean, integer)
#8 /srv/mediawiki/w/includes/specialpage/ChangesListSpecialPage.php(348): SpecialRecentChanges->outputChangesList(ResultWrapper, FormOptions)
#9 /srv/mediawiki/w/includes/specialpage/ChangesListSpecialPage.php(77): ChangesListSpecialPage->webOutput(ResultWrapper, FormOptions)
#10 /srv/mediawiki/w/includes/specials/SpecialRecentchanges.php(64): ChangesListSpecialPage->execute(NULL)
#11 /srv/mediawiki/w/includes/specialpage/SpecialPage.php(384): SpecialRecentChanges->execute(NULL)
#12 /srv/mediawiki/w/includes/specialpage/SpecialPageFactory.php(553): SpecialPage->run(NULL)
#13 /srv/mediawiki/w/includes/MediaWiki.php(281): SpecialPageFactory::executePath(Title, RequestContext)
#14 /srv/mediawiki/w/includes/MediaWiki.php(714): MediaWiki->performRequest()
#15 /srv/mediawiki/w/includes/MediaWiki.php(508): MediaWiki->main()
#16 /srv/mediawiki/w/index.php(41): MediaWiki->run()
#17 {main}
```
Tried to ran update.php on it:
```
Done 0 files in 0.0 seconds
Updating *_from_namespace fields in links tables.
...doing page_id from 1 to 200
Populating links tables...
Processing post spymgpj3pv7v8cya
Processing post sq196ojla9jx2zrm
Processing post sq2a02rybdvqk5g2
Processing post sqfyzamf4rnxxms2
Processing post sqfyzuotzsvs5tw2
Processing post sqfz0azp95melzte
Processing post sqfz225n5me823ki
Processing post sqxkg9x3t5ubyavm
Processing post sr09hrbv5vhuv5aq
Processing post ss0n5erk7t1smwlu
Processing post ss0n79hoowgk37v6
Processing post ss1w2648fej7qkr6
Processing post stt3ue6bc23ek1hu
Processing post stzezghhakmsc68i
Processing post su1l1vj5g065h1g2
Processing post su1ydy1ttszayaaa
Processing post su1yf12f9bnnp9ci
Processing post su208cx20g21fqtu
[cb5640fc] [no req] Flow\Exception\FailCommitException from line 119 of /srv/mediawiki/w/extensions/Flow/includes/Model/Workflow.php: No page for workflow: O:19:"Flow\Model\Workflow":9:{s:5:"*id";O:15:"Flow\Model\UUID":1:{s:20:"*alphadecimalValue";s:16:"su208cwyw76qrdea";}s:7:"*type";s:5:"topic";s:7:"*wiki";s:22:"permanentfuturelabwiki";s:9:"*pageId";i:0;s:12:"*namespace";i:3;s:12:"*titleText";s:12:"Samir_Lahiri";s:14:"*lastUpdated";s:14:"20151206180950";s:8:"*title";N;s:13:"*ownerTitle";O:5:"Title":7:{s:10:"mNamespace";i:3;s:10:"mDbkeyform";s:12:"Samir_Lahiri";s:9:"mFragment";s:0:"";s:10:"mInterwiki";s:0:"";s:22:"TitlemLocalInterwiki";b:0;s:17:"*mUserCaseDBKey";s:12:"Samir_Lahiri";s:17:"mDefaultNamespace";i:0;}}
Backtrace:
#0 [internal function]: Flow\Model\Workflow::toStorageRow(Flow\Model\Workflow)
#1 /srv/mediawiki/w/extensions/Flow/includes/Data/Mapper/CachingObjectMapper.php(128): call_user_func(array, Flow\Model\Workflow)
#2 [internal function]: Flow\Data\Mapper\CachingObjectMapper->normalizeRow(array)
#3 /srv/mediawiki/w/extensions/Flow/includes/Data/Index/FeatureIndex.php(428): array_map(array, array)
#4 /srv/mediawiki/w/extensions/Flow/includes/Data/ObjectLocator.php(80): Flow\Data\Index\FeatureIndex->findMulti(array, array)
#5 /srv/mediawiki/w/extensions/Flow/includes/Data/ObjectLocator.php(195): Flow\Data\ObjectLocator->findMulti(array)
#6 /srv/mediawiki/w/extensions/Flow/includes/Data/ObjectLocator.php(169): Flow\Data\ObjectLocator->getMulti(array)
#7 /srv/mediawiki/w/extensions/Flow/includes/Collection/AbstractCollection.php(230): Flow\Data\ObjectLocator->get(Flow\Model\UUID)
#8 /srv/mediawiki/w/extensions/Flow/maintenance/FlowPopulateLinksTables.php(105): Flow\Collection\AbstractCollection->getWorkflow()
#9 /srv/mediawiki/w/extensions/Flow/maintenance/FlowPopulateLinksTables.php(31): FlowPopulateLinksTables->processPosts(Flow\Data\Listener\ReferenceRecorder)
#10 /srv/mediawiki/w/maintenance/Maintenance.php(1318): FlowPopulateLinksTables->doDBUpdates()
#11 /srv/mediawiki/w/maintenance/update.php(181): LoggedUpdateMaintenance->execute()
#12 /srv/mediawiki/w/maintenance/doMaintenance.php(103): UpdateMediaWiki->execute()
#13 /srv/mediawiki/w/maintenance/update.php(214): require_once(string)
#14 {main}
```
Configuration:
https://github.com/miraheze/mw-config/blob/fa03000177393523085ae42642769137a23a4b98/LocalSettings.php
https://github.com/miraheze/mw-config/blob/fa03000177393523085ae42642769137a23a4b98/LocalExtensions.php#L35
Flow's REL1_26 branch (981e2ff36c2c4020617e69b71e35c084cba7013d)
MediaWiki 1.26.2, HHVM 3.9.1, MariaDB 10.0, Debian 8
https://permanentfuturelab.wiki/wiki/Special:RecentChanges (note: DNS routes you to a production MediaWiki 1.25 server. This error was reproduced on MediaWiki 1.26.)