Gmx covar range checking error

GROMACS version: 2021
GROMACS modification: Yes/No
Dear All,
I am using gromacs on windows 10 WSL2 ubuntu.
While running - gmx covar -s step4.0_minimization.tpr -f outputbox.xtc -n proteinAB_SAM_G3A_Nacl.ndx, i got following error

Range checking error (possible bug):
The provided structure file only contains 42820 coordinates, but coordinate
index 3993 was requested for fitting. Make sure to update structure files and
index files if you store only a part of your system.

however I centred the the chains using gmx trjconv without any error.

Thank you
Best Regards


there was a bug on gmx covar that was fix 2021.1
you can try to update your version to 2021.2