Internal error
[b3ad7572696a92022b0abc31] /index.php?title=Formal_grammars_-_regular_expressions,_CFGs,_formal_language&diff=prev&oldid=78668 MediaWiki\Revision\RevisionAccessException: Failed to load data blob from Expected array in serialized string for revision 78667. If this problem persist, use the findBadBlobs maintenance script to investigate the issue and mark bad blobs.
Backtrace:
from /data/db_ssd/var-www/wiki-helpful/includes/Revision/RevisionStore.php(1193)
#0 /data/db_ssd/var-www/wiki-helpful/includes/Revision/RevisionStore.php(1507): MediaWiki\Revision\RevisionStore->loadSlotContent()
#1 [internal function]: MediaWiki\Revision\RevisionStore->MediaWiki\Revision\{closure}()
#2 /data/db_ssd/var-www/wiki-helpful/includes/Revision/SlotRecord.php(324): call_user_func()
#3 /data/db_ssd/var-www/wiki-helpful/includes/diff/DifferenceEngine.php(388): MediaWiki\Revision\SlotRecord->getContent()
#4 /data/db_ssd/var-www/wiki-helpful/includes/diff/DifferenceEngine.php(361): DifferenceEngine->loadSingleSlot()
#5 /data/db_ssd/var-www/wiki-helpful/includes/diff/DifferenceEngine.php(308): DifferenceEngine->getSlotContents()
#6 /data/db_ssd/var-www/wiki-helpful/includes/diff/DifferenceEngine.php(1183): DifferenceEngine->getSlotDiffRenderers()
#7 /data/db_ssd/var-www/wiki-helpful/includes/diff/DifferenceEngine.php(892): DifferenceEngine->showDiffStyle()
#8 /data/db_ssd/var-www/wiki-helpful/includes/page/Article.php(952): DifferenceEngine->showDiffPage()
#9 /data/db_ssd/var-www/wiki-helpful/includes/page/Article.php(486): Article->showDiffPage()
#10 /data/db_ssd/var-www/wiki-helpful/includes/actions/ViewAction.php(78): Article->view()
#11 /data/db_ssd/var-www/wiki-helpful/includes/MediaWiki.php(556): ViewAction->show()
#12 /data/db_ssd/var-www/wiki-helpful/includes/MediaWiki.php(333): MediaWiki->performAction()
#13 /data/db_ssd/var-www/wiki-helpful/includes/MediaWiki.php(923): MediaWiki->performRequest()
#14 /data/db_ssd/var-www/wiki-helpful/includes/MediaWiki.php(576): MediaWiki->main()
#15 /data/db_ssd/var-www/wiki-helpful/index.php(50): MediaWiki->run()
#16 /data/db_ssd/var-www/wiki-helpful/index.php(46): wfIndexMain()
#17 {main}