Running gmx_MMPBSA for gromacs files

Dear Gromacs users,

I am trying to calculate binding free energy between protein and ligand using gmx_MMPBSA package. My trajectory and topology file (stripped of water and ions) were created successfully, however when running gmx_MMPBSA I get the following error:

"PrmtopError: provided receptor/ligand masks don’t select every atom in the complex topology!

Exiting. All files have been retained."

I will post my mmpbsa input script below if that helps:

Input file for running PB and GB in serial

&general

endframe=50, keep_files=2,

/

&gb

igb=2, saltcon=0.100,

/

&pb

istrng=0.100,

/

Many thanks for any ideas in advance

Hi.
gmx_MMPBSA is not part of the Gromacs tools package. Please consult our group (https://groups.google.com/g/gmx_mmpbsa) directly or open an issue on Github (Issues · Valdes-Tresanco-MS/gmx_MMPBSA · GitHub) for proper follow-up
HTH!
Mario S.