If you upgrade to Solr 7, you can get this error:
TokenizerFactory is using deprecated 5.5.0 emulation. You should at some point declare and reindex to at least 6.0,​ because 5.x emulation is deprecated and will be removed in 7.0
I was able to fix this by updating the Lucene version in solrconfig.xml for the core:
To make this take effect, I unloaded the core, deleted the data, made the change, and re-indexed.