Hello, I get NPE when I use IndexSearcher.explain(). Checked with Lucene 8.6.0 and 8.6.2.
The query: (lorem AND NOT "dolor lorem") OR ipsum The text: dolor lorem ipsum Stack trace: > java.lang.NullPointerException > at java.util.Objects.requireNonNull(Objects.java:203) > at org.apache.lucene.search.LeafSimScorer.<init>(LeafSimScorer.java:38) > at > org.apache.lucene.search.spans.SpanWeight.explain(SpanWeight.java:160) > at org.apache.lucene.search.BooleanWeight.explain(BooleanWeight.java:87) > at org.apache.lucene.search.BooleanWeight.explain(BooleanWeight.java:87) > at > org.apache.lucene.search.IndexSearcher.explain(IndexSearcher.java:716) > at > org.apache.lucene.search.IndexSearcher.explain(IndexSearcher.java:693) The sample code: val analyzer = new StandardAnalyzer(); val query = new ComplexPhraseQueryParser("", analyzer).parse(queryString); final MemoryIndex memoryIndex = new MemoryIndex(true); memoryIndex.addField("", text, analyzer); final IndexSearcher searcher = memoryIndex.createSearcher(); final TopDocs topDocs = searcher.search(query, 1); final ScoreDoc match = topDocs.scoreDocs[0]; searcher.explain(query, match.doc); -- Michał Słomkowski