Previously I had
.Net.Search.Similarity.Default = New LuceneIgnoreSimilarity According to the migration Guide : LUCENE-2236<https://issues.apache.org/jira/browse/LUCENE-2236>, LUCENE-2912<https://issues.apache.org/jira/browse/LUCENE-2912>: DefaultSimilarity can no longer be set statically (and dangerously) for the entire JVM. Similarity can now be configured on a per-field basis (via PerFieldSimilarityWrapper) Similarity has a lower-level API, if you want the higher-level vector-space API like in previous Lucene releases, then look at TFIDFSimilarity. How can I configure this per field? Any examples you would like to share? Found this online but this method doesn't exist IndexWriterConfig config = new IndexWriterConfig(analyzer); config.setSimilarity(perFieldSimilarities);