Problem while running the simulation?

I found the following message while running my simulation,

G4ParticleChange::CheckIt : the global time goes back !!
6: Difference: 0.0231658[ns]
6: G4ParticleChange::CheckIt
6: -----------------------------------------------
6: G4ParticleChange Information
6: -----------------------------------------------
6: # of 2ndaries : 0
6: -----------------------------------------------
6: Energy Deposit (MeV): 0
6: Non-ionizing Energy Deposit (MeV): 0
6: Track Status : Alive
6: True Path Length (mm) : -6.94
6: Stepping Control : 0
6: Mass (GeV) : 0
6: Charge (eplus) : 0
6: MagneticMoment : 0
6: : = 0*[e hbar]/[2 m]
6: Position - x (mm) : 0.836
6: Position - y (mm) : 0.0903
6: Position - z (mm) : 0.307
6: Time (ns) : -0.0118
6: Proper Time (ns) : 0
6: Momentum Direct - x : -0.934
6: Momentum Direct - y : 0.101
6: Momentum Direct - z : 0.343
6: Kinetic Energy (MeV): 0.0457
6: Polarization - x : 0
6: Polarization - y : 0
6: Polarization - z : 0
6: Touchable (pointer) : 0x2d854a8
6:
6:*** G4Exception : 200
6: issued by : G4ParticleChange::CheckIt
6:momentum, energy, and/or time was illegal
6:*** Event Must Be Aborted

What exactly is this message about?.

Thank you for helping.

Hello,

This type of problem may happens if geometry description if incorrect, for example, big overlap of volumes.

VI