DeviceAgentVector out of scope.

[Robadob]

FLAMEGPU_HOST_FUNCTION(DeviceAgentVectorBirth) {
    DeviceAgentVector vec_a = FLAMEGPU->agent("agent", "a").getPopulationData();
    DeviceAgentVector vec_b = FLAMEGPU->agent("agent", "b").getPopulationData();
    const uint32_t birth_ct_a = vec_a.size();  // Access violation here
    const uint32_t birth_ct_b = vec_b.size();
}

vec_a is owned by the temporary object created by FLAMEGPU->agent("agent", "a"), as such by the time it is used it has been deallocated.

Presumed fix would be centralise the storage inside the main HostAPI object or the respective CUDAAgent.