"lbzip2 -t /public/dumps/public/wikidatawiki/20160801/wikidatawiki-20160801-pages-articles.xml.bz2" succeeds for me on Labs. You should compare the checksum of your copy with https://dumps.wikimedia.org/wikidatawiki/20160801/wikidatawiki-20160801-sha1... (says c6a823508240d161e481e5d0045921421a9db5f1 wikidatawiki-20160801-pages-articles.xml.bz2 ).

Nemo