Class Wikibase\DataModel\Entity\ItemId not found WikiBase installation

Question

I am currently trying to follow this tutorial: https://www.mediawiki.org/wiki/Wikibase/Installation

I have the latest version of both MediaWiki and WikiBase (1.35) I'm currently trying to run the maintenance scripts. I have installed both Wikibase Repository and Wikibase Client.

When I try to run "php maintenance/update.php" it gives me this error:

Error from line 47 of /Applications/XAMPP/xamppfiles/htdocs/mywikiname/extensions/Wikibase/lib/WikibaseLib.entitytypes.php: Class "Wikibase\DataModel\Entity\ItemId" not found
#0 /Applications/XAMPP/xamppfiles/htdocs/mywikiname/extensions/Wikibase/repo/includes/WikibaseRepo.php(695): require()
#1 /Applications/XAMPP/xamppfiles/htdocs/mywikiname/extensions/Wikibase/repo/includes/WikibaseRepo.php(410): Wikibase\Repo\WikibaseRepo::getDefaultEntityTypes()
#2 /Applications/XAMPP/xamppfiles/htdocs/mywikiname/extensions/Wikibase/repo/includes/WikibaseRepo.php(460): Wikibase\Repo\WikibaseRepo::newInstance()
#3 /Applications/XAMPP/xamppfiles/htdocs/mywikiname/extensions/Wikibase/repo/includes/RepoHooks.php(115): Wikibase\Repo\WikibaseRepo::getDefaultInstance()
#4 /Applications/XAMPP/xamppfiles/htdocs/mywikiname/includes/HookContainer/HookContainer.php(321): Wikibase\Repo\RepoHooks::onSetupAfterCache()
#5 /Applications/XAMPP/xamppfiles/htdocs/mywikiname/includes/HookContainer/HookContainer.php(132): MediaWiki\HookContainer\HookContainer->callLegacyHook(string, array, array, array)
#6 /Applications/XAMPP/xamppfiles/htdocs/mywikiname/includes/HookContainer/HookRunner.php(3417): MediaWiki\HookContainer\HookContainer->run(string, array)
#7 /Applications/XAMPP/xamppfiles/htdocs/mywikiname/includes/Setup.php(694): MediaWiki\HookContainer\HookRunner->onSetupAfterCache()
#8 /Applications/XAMPP/xamppfiles/htdocs/mywikiname/includes/WebStart.php(89): require_once(string)
#9 /Applications/XAMPP/xamppfiles/htdocs/mywikiname/index.php(44): require(string)
#10 {main}

How can I fix this? I've tried updating Composer and reinstalling it numerous times. If anyone can help, that would be great! :)

Answer 1

I hit the same error, and in my case, it was because my compose.local.json, (copied from composer.local.json-sample,) was pointing to "extensions/example/composer.json" rather than "extensions/Wikibase/composer.json". Fixing this to Wikibase, deleting composer.lock, running composer install --no-dev again, and finally running update.php fixed the issue.