[gmx-users] MD stopped

[Tanos]

    Hi Folks,
    I was peforming a MD of 1 ns but it suddenly stopped and sent me the 
following message :

t = 599.086 ps: Water molecule starting at atom 123889 can not be settled.
Check for bad contacts and/or reduce the timestep.Wrote pdb files with 
previous and current coordinates
Large VCM(group rest): 284531215040512.00000, -217004363481088.00000, 
245415253377024.00000, ekin-cm:  7.75014e+34

    Does someone knows what does it means ????
    Is that a bug or can I ignore this mesage and restart the MD  from 
where it stopped ????
     Thanks in advance.
     Tanos C. C. Franca