Hi, > thanks. Indeed it seems that the error is triggered by declaring a field > as 'Optional'.
That I doubt, due to established tests https://github.com/datanucleus/tests/blob/master/jdo/general/src/test/org/datanucleus/tests/types/OptionalTest.java More likely the problem is down to having a field as Optional<Object>, which is a minority interest use-case IMHO (which can often be symptomatic of a problem in a model, with lack of use of inheritance etc). Perhaps try nightly builds of jars if having problems. > Next step is likely to update the implementation. DataNucleus has supported Optional since 5.0.0-m1, and tested on Optional<{basic}>, Optional<PC> (see link). It hasn't been tested on Optional<Object> where Object refers to potentially multiple types of PC. Regards -- Andy DataNucleus (Web: http://www.datanucleus.org Twitter: @datanucleus)
