RuntimeError: Object "C12" does not exist in object

Hi, everyone.

I got this problem ‘RuntimeError: Object “C12” does not exist in object’

Firstly, I struggled on ‘cross_section’ but solved with

openmc.Materials.cross_sections = ‘path/to/cross_section.xml’

Next, the C12, C13 and O18 not found in ‘cross_section.xml’ and I solved it with adding another command line for C12, C13 using C0.h5 (direct them to C0.h5 file). I also do the same with O18.

However, I struck with the ‘RuntimeError: Object “C12” does not exist in object / -------------------------------------------------------------------------- MPI_ABORT was invoked on rank 0 in communicator MPI_COMM_WORLD Proc: [[47536,0],0] Errorcode: -1 NOTE: invoking MPI_ABORT causes Open MPI to kill all MPI processes. You may or may not see output from other processes, depending on exactly when Open MPI kills them.’

I can’t find any solution so far.
What should i do? T_T