An InternalException occurs when gets an result list

[ObjectDB 2.6.4_04] Unexpected exception (Error 990)
Generated by Java HotSpot(TM) Client VM 1.8.0_51 (on Windows 7 6.1).
Please report this error on http://www.objectdb.com/database/issue/new
com.objectdb.o.InternalException: java.lang.NullPointerException: null
java.lang.NullPointerException
at com.objectdb.o.VAR.S(VAR.java:297)
at com.objectdb.o.VAR.R(VAR.java:259)
at com.objectdb.o.SYR.y(SYR.java:515)
at com.objectdb.o.QRC.x(QRC.java:192)
at com.objectdb.o.QRM.Vm(QRM.java:272)
at com.objectdb.o.MST.Vm(MST.java:988)
at com.objectdb.o.WRA.Vm(WRA.java:311)
at com.objectdb.o.WSM.Vm(WSM.java:115)
at com.objectdb.o.QRR.g(QRR.java:247)
at com.objectdb.o.QRR.f(QRR.java:153)
at com.objectdb.jpa.JpaQuery.getResultList(JpaQuery.java:716)

Could you please post more information, including details about the query?

The stack trace indicates an unexpected query variable.

Are there non entity variables in the query or an entity class with no instances in the database yet?

it is actually a simple query:

select distinct m from ArchitectureImpl m

with query option: query.setHint("objectdb.result-fetch", "LAZY");

The exception is thrown during query compilation in checking the variable type.

Could you please check if ArchitectureImpl is defined as an entity class? Does it have instances in the database? Has it been converted to entity class from a non entity class?

The ArchitectureImpl was not known by the ObjectDB in our OSGi environment.

The solution is we make all entities known at the ObjectDB and use the full qualified class name in all querys.