Hibernate Search 6.0.0.Beta6 simplequerydsl breaking

Hibernate Search
3

Attaching the relevant stacktrace:

java.lang.NullPointerException
	at org.hibernate.search.backend.elasticsearch.search.predicate.impl.ElasticsearchSimpleQueryStringPredicateBuilder.doBuild(ElasticsearchSimpleQueryStringPredicateBuilder.java:141)
	at org.hibernate.search.backend.elasticsearch.search.predicate.impl.AbstractElasticsearchSearchPredicateBuilder.build(AbstractElasticsearchSearchPredicateBuilder.java:49)
	at org.hibernate.search.backend.elasticsearch.search.predicate.impl.ElasticsearchSearchPredicate.build(ElasticsearchSearchPredicate.java:28)
	at org.hibernate.search.backend.elasticsearch.search.predicate.impl.ElasticsearchBooleanPredicateBuilder.contributeClauses(ElasticsearchBooleanPredicateBuilder.java:142)
	at org.hibernate.search.backend.elasticsearch.search.predicate.impl.ElasticsearchBooleanPredicateBuilder.doBuild(ElasticsearchBooleanPredicateBuilder.java:108)
	at org.hibernate.search.backend.elasticsearch.search.predicate.impl.AbstractElasticsearchSearchPredicateBuilder.build(AbstractElasticsearchSearchPredicateBuilder.java:49)
	at org.hibernate.search.backend.elasticsearch.search.predicate.impl.ElasticsearchSearchPredicate.build(ElasticsearchSearchPredicate.java:28)
	at org.hibernate.search.backend.elasticsearch.search.predicate.impl.ElasticsearchSearchPredicateBuilderFactoryImpl.contribute(ElasticsearchSearchPredicateBuilderFactoryImpl.java:79)
	at org.hibernate.search.backend.elasticsearch.search.predicate.impl.ElasticsearchSearchPredicateBuilderFactoryImpl.contribute(ElasticsearchSearchPredicateBuilderFactoryImpl.java:41)
	at org.hibernate.search.engine.search.query.dsl.spi.AbstractSearchQueryOptionsStep.contribute(AbstractSearchQueryOptionsStep.java:193)
	at org.hibernate.search.engine.search.query.dsl.spi.AbstractSearchQueryOptionsStep.where(AbstractSearchQueryOptionsStep.java:68)
	at org.hibernate.search.engine.search.query.dsl.impl.DefaultSearchQuerySelectStep.where(DefaultSearchQuerySelectStep.java:92)
	at org.hibernate.search.engine.search.query.dsl.spi.AbstractDelegatingSearchQuerySelectStep.where(AbstractDelegatingSearchQuerySelectStep.java:74)

And here is the code that builds the query predicate:

return searchSession.search(searchScope).where(searchScope.predicate().bool(b -> {
            //making sure cross-customer data is not shown
            b.must(searchScope.predicate().match().field("customerId").matching(customerId));

            //matching objects according to presence of user query
            if (StringUtils.isBlank(finalQuery)) {
                b.must(searchScope.predicate().matchAll());
            } else {
                b.must(searchScope.predicate().simpleQueryString().fields()
                        .matching(SearchUtil.getLuceneQuery(finalQuery)));
            }

            //apply user table filter
            if (StringUtils.isNotBlank(filter)) {
                String[] filters = filter.split(";");
                for (String tempFilter : filters) {
                    String[] filterArray = tempFilter.split("=");
                    String[] filterValues = filterArray[1].split(",");
                    b.must(searchScope.predicate().bool(c -> {
                        for (String filterValue : filterValues) {
                            c.should(searchScope.predicate().match().field(filterArray[0]).matching(filterValue));
                        }
                    }));
                }
            }

            //apply global account filter
            if (!ObjectUtils.isEmpty(accountIds)) {
                b.must(searchScope.predicate().bool(c -> {
                    for (String accountId : accountIds) {
                        c.should(searchScope.predicate().match().field("accountId").matching(accountId));
                    }
                }));
            }

            //apply predicates for metrics if required
            if (!ObjectUtils.isEmpty(booleanPredicateClausesSteps)) {
                for (BooleanPredicateClausesStep booleanPredicateClausesStep : booleanPredicateClausesSteps)
                    b.must(booleanPredicateClausesStep);
            }

        }).toPredicate());