[lammps-users] Fatal when using REAX potential

Dear all lammps users,

When I using the REAX potential, after the Screen Output give the information “Setting up run …”
There is a line:

-Fatal: Unknown bond in molecule

and then the executable lammps program stopped.

What does this Error mean? I have never seen the error starts with “-Fatal”
I try to search it in the manual and the code, however, I can’t find more details.

Can anybody please advise on how I can solve this problem? Thank you all very much.