Hi,
CH4 with symmetry? Perhaps the input is simply too small to run it in parallel on many CPUs?
For CH4 and frozen cores there are only 4 occupied orbitals in C1.
If you have less non-frozen occupied orbitals than CPUs, I am not sure if that will work in all cases. It usually does, though.
Did you also try the SMP instead of the MPI version? I just did MP2 gradients for CH4 with aug-cc-pVQZ on 8 CPUs in C1 and there were no errors.
Regards,
Uwe