Internal error

[2335b693106caf80ccdb3626] /w/index.php?title=Special:UniversalExport/Finding_Little_Blue&ue%5Bmodule%5D=html Error from line 63 of /var/www/bluespice/w/extensions/BlueSpiceUEModuleHTML/includes/ExportModuleHTML.php: Class 'BsPDFPageProvider' not found

Backtrace:

#0 /var/www/bluespice/w/extensions/BlueSpiceUniversalExport/includes/specials/SpecialUniversalExport.class.php(191): ExportModuleHTML->createExportFile(SpecialUniversalExport)
#1 /var/www/bluespice/w/extensions/BlueSpiceUniversalExport/includes/specials/SpecialUniversalExport.class.php(117): SpecialUniversalExport->processParameter(string)
#2 /var/www/bluespice/w/includes/specialpage/SpecialPage.php(565): SpecialUniversalExport->execute(string)
#3 /var/www/bluespice/w/includes/specialpage/SpecialPageFactory.php(568): SpecialPage->run(string)
#4 /var/www/bluespice/w/includes/MediaWiki.php(288): SpecialPageFactory::executePath(Title, RequestContext)
#5 /var/www/bluespice/w/includes/MediaWiki.php(818): MediaWiki->performRequest()
#6 /var/www/bluespice/w/includes/MediaWiki.php(524): MediaWiki->main()
#7 /var/www/bluespice/w/index.php(42): MediaWiki->run()
#8 {main}