[gmx-users] changing the version of file

[Souilem Safa]

Dear Gromacs users,

I'm aiming to extract a frame file from a reduced trajectory, i did the
simulation on gromacs version 4.6.1 and I would like to do my analysis in
gromacs 4.5.6 for availability reasons.
When I entered my command , I got this error :
 reading tpx file (md.tpr) version 83 with version 73 program

Can any one help me how shoud I do to overcome this problem?
Many thanks
Safa