WinCache has a limit to the key size of 150 characters. Among other things, wincache_lock crashes on a longer key because of limits to the length of a Windows Mutex.
A stack trace of this issue looks like this:
PHP Fatal error: wincache_lock(): lock key should be less than 150 characters in .\includes\libs\objectcache\WinCacheBagOStuff.php on line 55
PHP Stack trace:
PHP 1. {main}() .\index.php:0
PHP 2. MediaWiki->run() .\index.php:42
PHP 3. MediaWiki->main() .\includes\MediaWiki.php:524
PHP 4. MediaWiki->performRequest() .\includes\MediaWiki.php:861
PHP 5. MediaWiki->performAction() .\includes\MediaWiki.php:294
PHP 6. ViewAction->show() .\includes\MediaWiki.php:500
PHP 7. Article->view() .\includes\actions\ViewAction.php:68
PHP 8. PoolWorkArticleView->execute() .\includes\page\Article.php:604
PHP 9. PoolWorkArticleView->doWork() .\includes\poolcounter\PoolCounterWork.php:123
PHP 10. WikitextContent->getParserOutput() .\includes\poolcounter\PoolWorkArticleView.php:144
PHP 11. WikitextContent->fillParserOutput() .\includes\content\AbstractContent.php:516
PHP 12. Parser->parse() .\includes\content\WikitextContent.php:323
PHP 13. Parser->internalParse() .\includes\parser\Parser.php:443
PHP 14. Parser->formatHeadings() .\includes\parser\Parser.php:1327
PHP 15. Parser::normalizeSectionName() .\includes\parser\Parser.php:4245
PHP 16. MediaWikiTitleCodec->splitTitleString() .\includes\parser\Parser.php:5867
PHP 17. MediaWiki\Interwiki\ClassicInterwikiLookup->isValidInterwiki() .\includes\title\MediaWikiTitleCodec.php:334
PHP 18. MediaWiki\Interwiki\ClassicInterwikiLookup->fetch() .\includes\interwiki\ClassicInterwikiLookup.php:131
PHP 19. MediaWiki\Interwiki\ClassicInterwikiLookup->load() .\includes\interwiki\ClassicInterwikiLookup.php:155
PHP 20. WANObjectCache->getWithSetCallback() .\includes\interwiki\ClassicInterwikiLookup.php:298
PHP 21. WANObjectCache->doGetWithSetCallback() .\includes\libs\objectcache\WANObjectCache.php:1114
PHP 22. WANObjectCache->set() .\includes\libs\objectcache\WANObjectCache.php:1262
PHP 23. WinCacheBagOStuff->merge() .\includes\libs\objectcache\WANObjectCache.php:546
PHP 24. wincache_lock() .\includes\libs\objectcache\WinCacheBagOStuff.php:55Proposed Fix
Run the object cache keys through a fixed-length digest (going to try MD5 at first) before querying WinCache.