Fatal error in gromacs

GROMACS version:
GROMACS modification: Yes/No

Hi everyone,

I am beginners in GROMACS and I am trying one tutorial on youtube by Molecular Dynamics Tutorial | Protein-Ligand Complex: GROMACS - PART 1 - YouTube. However, there were some errors as shown below:

Fatal error:
atom C1 not found in buiding block 1MET while combining tdb and rtp

May I know how to solve this because in that tutorial, this error was not appear despite I am using the similar protein given. Thank you.

Answered here: Newest CHARMM36 port for GROMACS - #11 by jalemkul