# ERROR: Unknown left-hand XXXX in parameter file **URL:** \ **Category:** User discussions\ **Created:** [May 18, 2020, 2:17pm UTC](https://gromacs.bioexcel.eu/t/error-unknown-left-hand-xxxx-in-parameter-file/154 "2020-05-18T14:17:51Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![mjsubach](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/mjsubach/32/387_2.png) [@mjsubach](https://gromacs.bioexcel.eu/u/mjsubach)\ **Post date:** [May 18, 2020, 2:17pm UTC](https://gromacs.bioexcel.eu/t/error-unknown-left-hand-xxxx-in-parameter-file/154/1 "2020-05-18T14:17:51Z")
Hello I am completing Tutorial 1, Step Six: Equilibration and input: gmx grompp -f nvt.mdp -c em.gro -r em.gro -p topol.top -o nvt.tpr and received the error: WARNING 1 [file nvt.mdp, line 52]: Unknown left-hand ‘\outl0\strokewidth0 \strokec2 title’ in parameter file Prior to my input I created the .mdp textedit file below: title = OPLS Lysozyme NVT equilibration define = -DPOSRES ; position restrain the protein ; Run parameters integrator = md ; leap-frog integrator nsteps = 50000 ; 2 \* 50000 = 100 ps dt = 0.002 ; 2 fs ; Output control nstxout = 500 ; save coordinates every 1.0 ps nstvout = 500 ; save velocities every 1.0 ps nstenergy = 500 ; save energies every 1.0 ps nstlog = 500 ; update log file every 1.0 ps ; Bond parameters continuation = no ; first dynamics run constraint\_algorithm = lincs ; holonomic constraints constraints = h-bonds ; bonds involving H are constrained lincs\_iter = 1 ; accuracy of LINCS lincs\_order = 4 ; also related to accuracy ; Nonbonded settings cutoff-scheme = Verlet ; Buffered neighbor searching ns\_type = grid ; search neighboring grid cells nstlist = 10 ; 20 fs, largely irrelevant with Verlet rcoulomb = 1.0 ; short-range electrostatic cutoff (in nm) rvdw = 1.0 ; short-range van der Waals cutoff (in nm) DispCorr = EnerPres ; account for cut-off vdW scheme ; Electrostatics coulombtype = PME ; Particle Mesh Ewald for long-range electrostatics pme\_order = 4 ; cubic interpolation fourierspacing = 0.16 ; grid spacing for FFT ; Temperature coupling is on tcoupl = V-rescale ; modified Berendsen thermostat tc-grps = Protein Non-Protein ; two coupling groups - more accurate tau\_t = 0.1 0.1 ; time constant, in ps ref\_t = 300 300 ; reference temperature, one for each group, in K ; Pressure coupling is off pcoupl = no ; no pressure coupling in NVT ; Periodic boundary conditions pbc = xyz ; 3-D PBC ; Velocity generation gen\_vel = yes ; assign velocities from Maxwell distribution gen\_temp = 300 ; temperature for Maxwell distribution gen\_seed = -1 ; generate a random seed The GROMACS error website recommended: ### Unknown left-hand XXXX in parameter file [grompp] has found an unknown term in the [.mdp file](http://www.gromacs.org/Documentation/File_Formats/.mdp_File) fed to it. You should check the spelling of XXXX and look for typographical errors. Be aware that quite a few run parameters changed between GROMACS 3.x and GROMACS 4.x and the output from [grompp](http://www.gromacs.org/Documentation/Gromacs_Utilities/grompp) will sometimes offer helpful commentary about these situations. Can somebody please assist me with what is wrong with my mdp file input into textedit? I am using GROMACS: gmx grompp, version 2019.6 Thanks:) Joel mjsubach@ncsu.edu ---
**Author:** ![jalemkul](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/jalemkul/32/18_2.png) [@jalemkul](https://gromacs.bioexcel.eu/u/jalemkul)\ **Post date:** [May 18, 2020, 2:29pm UTC](https://gromacs.bioexcel.eu/t/error-unknown-left-hand-xxxx-in-parameter-file/154/2 "2020-05-18T14:29:37Z")
The textedit program is a rich-text editor and will embed formatting characters into your files. Do not use word processing software or rich-text editors when dealing with plain-text simulation input/output files. You will break their format. Only use plain-text editors. ---
**Author:** ![mjsubach](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/mjsubach/32/387_2.png) [@mjsubach](https://gromacs.bioexcel.eu/u/mjsubach)\ **Post date:** [May 18, 2020, 2:43pm UTC](https://gromacs.bioexcel.eu/t/error-unknown-left-hand-xxxx-in-parameter-file/154/3 "2020-05-18T14:43:51Z")
Hell jalemkul and thank you for your kind update and I used this same TextEdit (Version 1.12 (329)) for the same tutorial Step-4 Add Ions and did not have this problem, with you now knowing this would you still recommend a different TextEdit? Kind Regards, Joel ---
**Author:** ![jalemkul](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/jalemkul/32/18_2.png) [@jalemkul](https://gromacs.bioexcel.eu/u/jalemkul)\ **Post date:** [May 18, 2020, 3:00pm UTC](https://gromacs.bioexcel.eu/t/error-unknown-left-hand-xxxx-in-parameter-file/154/4 "2020-05-18T15:00:32Z")
You shouldn’t have be using a text editor to make any changes to files. Maybe you saved before exiting when viewing one file but not another. But the advice remains - you cannot use a rich-text editor to manipulate any files that GROMACS reads. They will all break in the same way. ---
**Author:** ![mjsubach](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/mjsubach/32/387_2.png) [@mjsubach](https://gromacs.bioexcel.eu/u/mjsubach)\ **Post date:** [May 18, 2020, 3:25pm UTC](https://gromacs.bioexcel.eu/t/error-unknown-left-hand-xxxx-in-parameter-file/154/5 "2020-05-18T15:25:01Z")
Hello and thanks a bunch for your kind update, its working now:)