Error when generating e+e- source

I’m trying to generate an electron-positron pair source that shoots both particles at the same time.
I’m using the G4ParticleGun class. I have to read from an external file 1000 events. For each event I have the e- energy and its momentum direction and the e+ energy with its momentum direction. I have created a vertex inside my volume and I have associated to it, like in the particleGun : PrimaryGeneratorAction1 example, the electron and the positron with the properties read from the file.
When I execute my code I have the following error:

   G4EnergyRangeManager:GetHadronicInteraction: counter=2, Ek=nan, Material = Helium3, Element = helium3
*0* low=0, high=3500
*1* low=3000, high=1e+08
In /Applications/geant4.10.05/source/processes/hadronic/management/src/, line 128: 
===> GetHadronicInteraction: No Model found

-------- EEEE ------- G4Exception-START -------- EEEE -------
*** G4Exception : had005
      issued by : G4HadronicProcess::PostStepDoIt
In /Applications/geant4.10.05/source/processes/hadronic/management/src/, line 128: 
===> GetHadronicInteraction: No Model found
Target element helium3  Z= 2  A= 3
Unrecoverable error in the method ChooseHadronicInteraction of photonNuclear
TrackID= 2006  ParentID= 1994  gamma
Ekin(GeV)= nan;  direction= (nan,nan,nan)
Position(mm)= (nan,nan,nan);  material Helium3
PhysicalVolume  <Absorb_phys>
 No HadronicInteraction found out

*** Fatal Exception *** core dump ***
G4Track (0x10a075f50) - track ID = 2006, parent ID = 1994
 Particle type : gamma - creator process : annihil, creator model : annihil
 Kinetic energy : nan eV  - Momentum direction : (nan,nan,nan)
 Step length : 11.1734 m   - total energy deposit : 0 eV 
 Pre-step point : (nan,nan,nan) - Physical volume : Absorb_phys (Helium3)
 - defined by : Transportation - step status : 1
 Post-step point : (nan,nan,nan) - Physical volume : Absorb_phys (Helium3)
 - defined by : photonNuclear - step status : 4
 *** Note: Step information might not be properly updated.

-------- EEEE -------- G4Exception-END --------- EEEE -------

*** G4Exception: Aborting execution ***
Program ended with exit code: 9

If I substitute the e+ with a neutron I have no error.
I would really appreciated your assistance on how to implement correctly my source.

Thank you