[gmx-users] Invalid order for directive system

[Sahithya S Iyer]

Dear gmx users,

I am trying to run a martini CG membrane protein system. The required itps
are included in the top file --
include "martini_v2.2P.itp"
include "Protein.itp"
include "martini_v2.0_lipids_all_201506.itp"
include "martini_v2.0_ions.itp"

The itp file has restrains for protein backbone (Protein.itp) and phosphate
head group (martini_v2.0_lipids_all_201506.itp) of bilayer. This is
included in the equilibration mdp file as -
define  = -DFLEXIBLE  -DPOSRES

When i use the grompp command to generate a tpr i get the following error -

Fatal error:
Syntax error - File system.top, line 6
Last line read:
'[ system ]'
Invalid order for directive system

I thought i had given the order of the itp files correct. I have looked
though the previous answers on the same context, but it didn't rectify the
error. Can someone please tell me where i am going wrong..

Thanks,

Sahithya