Test-import fails

[Weissger]

After bringing up the vagrant box the data import with rdfio fails with following error:

`[6b7e64af6040433a16b7bebe] /w/index.php?title=Special:RDFImport Error from line 727 of /vagrant/w/vendor/semsol/arc2/store/ARC2_Store.php: Call to a member function escape() on null

Backtrace:

#0 /vagrant/w/vendor/semsol/arc2/store/ARC2_StoreQueryHandler.php(31): ARC2_Store->getTermID(string, string)
#1 /vagrant/w/vendor/semsol/arc2/store/ARC2_StoreSelectQueryHandler.php(1023): ARC2_StoreQueryHandler->getTermID(string, string)
#2 /vagrant/w/vendor/semsol/arc2/store/ARC2_StoreSelectQueryHandler.php(996): ARC2_StoreSelectQueryHandler->getTriplePatternSQL(array, string)
#3 /vagrant/w/vendor/semsol/arc2/store/ARC2_StoreSelectQueryHandler.php(1005): ARC2_StoreSelectQueryHandler->getPatternSQL(array, string)
#4 /vagrant/w/vendor/semsol/arc2/store/ARC2_StoreSelectQueryHandler.php(996): ARC2_StoreSelectQueryHandler->getDefaultPatternSQL(array, string)
#5 /vagrant/w/vendor/semsol/arc2/store/ARC2_StoreSelectQueryHandler.php(1005): ARC2_StoreSelectQueryHandler->getPatternSQL(array, string)
#6 /vagrant/w/vendor/semsol/arc2/store/ARC2_StoreSelectQueryHandler.php(996): ARC2_StoreSelectQueryHandler->getDefaultPatternSQL(array, string)
#7 /vagrant/w/vendor/semsol/arc2/store/ARC2_StoreSelectQueryHandler.php(924): ARC2_StoreSelectQueryHandler->getPatternSQL(array, string)
#8 /vagrant/w/vendor/semsol/arc2/store/ARC2_StoreSelectQueryHandler.php(475): ARC2_StoreSelectQueryHandler->getWHERESQL()
#9 /vagrant/w/vendor/semsol/arc2/store/ARC2_StoreSelectQueryHandler.php(68): ARC2_StoreSelectQueryHandler->getQuerySQL()
#10 /vagrant/w/vendor/semsol/arc2/store/ARC2_StoreSelectQueryHandler.php(36): ARC2_StoreSelectQueryHandler->getSQL()
#11 /vagrant/w/vendor/semsol/arc2/store/ARC2_Store.php(646): ARC2_StoreSelectQueryHandler->runQuery(array, integer)
#12 /vagrant/w/vendor/semsol/arc2/store/ARC2_Store.php(596): ARC2_Store->runQuery(array, string, integer, string)
#13 /vagrant/w/extensions/Rdfio/classes/RDFIO_ARC2StoreWrapper.php(138): ARC2_Store->query(string)
#14 /vagrant/w/extensions/Rdfio/classes/RDFIO_ARC2StoreWrapper.php(162): RDFIOARC2StoreWrapper->getURIForEquivURI(string, boolean)
#15 /vagrant/w/extensions/Rdfio/classes/parsers/RDFIO_URIToWikiTitleConverter.php(68): RDFIOARC2StoreWrapper->getWikiTitleByEquivalentURI(string)
#16 /vagrant/w/extensions/Rdfio/classes/parsers/RDFIO_URIToWikiTitleConverter.php(51): RDFIOURIToTitleConverter->getExistingTitleForURI(string)
#17 /vagrant/w/extensions/Rdfio/classes/parsers/RDFIO_ARC2ToWikiConverter.php(31): RDFIOURIToTitleConverter->convert(string)
#18 /vagrant/w/extensions/Rdfio/classes/RDFIO_RDFImporter.php(77): RDFIOARC2ToWikiConverter->convert(array, array, array)
#19 /vagrant/w/extensions/Rdfio/classes/RDFIO_RDFImporter.php(25): RDFIORDFImporter->importFromArc2Data(array, array, array)
#20 /vagrant/w/extensions/Rdfio/specials/SpecialRDFImport.php(83): RDFIORDFImporter->importRdfXml(string)
#21 /vagrant/w/extensions/Rdfio/specials/SpecialRDFImport.php(35): RDFImport->importData(RDFIORequestData)
#22 /vagrant/w/includes/specialpage/SpecialPage.php(522): RDFImport->execute(NULL)
#23 /vagrant/w/includes/specialpage/SpecialPageFactory.php(578): SpecialPage->run(NULL)
#24 /vagrant/w/includes/MediaWiki.php(287): SpecialPageFactory::executePath(Title, RequestContext)
#25 /vagrant/w/includes/MediaWiki.php(862): MediaWiki->performRequest()
#26 /vagrant/w/includes/MediaWiki.php(523): MediaWiki->main()
#27 /vagrant/w/index.php(43): MediaWiki->run()
#28 {main}`

Do you have an idea what might cause this problem?