[gmx-users] Error with "grompp"

[Elie M]

Dear all,
Maybe this error has been discussed before; I have checked previous messages on it but i could not resolve it. I have done a modified version of the oplsaa forcefield which I have called "ffoplsaamod.n2t". The top file was created successfully. However when I run grompp, I get the error:
"Fatal error:Syntax error - File ffoplsaabon.itp, line 306Last line read:'[ bondtypes ]'"
I tried to "uncomment" the bond types then the error moves to contraint types. What is the solution in this case?
N.B: I have copied the file ffoplsaa.itp and called it "ffoplsaamod.itp".. Not sure if this has anything to do with the error.
Thanks in advance,

Elie