Assert failed

[graue70]

PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX skos: <http://www.w3.org/2004/02/skos/core#>
PREFIX wd: <http://www.wikidata.org/entity/>
PREFIX wdt: <http://www.wikidata.org/prop/direct/>
SELECT ?alias WHERE {
  wd:Q1000299 (wdt:P734)?/(wdt:P297|wdt:P298|wdt:P1160|@en@wdt:P1813|@en@wdt:P1559|@en@wdt:P1477|@en@wdt:P1449|@en@wdt:P742|@en@skos:altLabel|@en@rdfs:label) ?alias .
}
ORDER BY ASC(?alias)

Exception: ASSERT FAILED (endBlock - beginBlock == 1; in ../src/index/CompressedRelation.cpp, line 218, function static void CompressedRelationMetaData::scan(Id, const Id&, IdTableImpl*, const Permutation&, ad_utility::SharedConcurrentTimeoutTimer) [with PermutationInfo = Permutation::PermutationImpl, std::equal_to, std::allocator > > > > >; IdTableImpl = detail::IdTableTemplated<0, detail::IdTableVectorWrapper >, ad_utility::AllocatorWithLimit >; Id = long unsigned int; ad_utility::SharedConcurrentTimeoutTimer = std::shared_ptr >])

If I replace Q1000299 by Q2843 there is no error.

[hannahbast]

@joka921 To my surprise, this query still yields the same error message. Any idea what is going wrong here?

[joka921]

I have minimized the nonworking example to the following query:

PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX skos: <http://www.w3.org/2004/02/skos/core#>
PREFIX wd: <http://www.wikidata.org/entity/>
PREFIX wdt: <http://www.wikidata.org/prop/direct/>
SELECT ?alias WHERE {
  wd:Q1000299 @en@wdt:P1477 ?alias .
}
ORDER BY ASC(?alias)

and I have already found the problem (that assertion should be <= 1 instead of ==0 to not wrongly fail in some special cases when no triples are found for a certain predicate.
I am working on fixing this.