MMPBSA error

[Tanmayee Basu]

Kindly guide me how can I rectify the following error I'm getting

The number of atoms in the topology (10096) and the complex structure (1884) are different. Please check these files and verify that they are correct. Otherwise report the error...

[Mario Sergio Valdes]

Probably, you are selecting the wrong groups in the index files... Please, attach the gmx_MMPBSA.log file

[Tanmayee Basu]

Thank you for your suggestion. 

After I chose the correct groups in the index file I got the following error:

MMPBSA_Error:

No residue for mutation was defined

[Mario Sergio Valdes]

Several variables in the input file must be defined by the user. One of them is mutant_res. 

I notice you are using all methods in the input file. Take care, this can take a long time to run