error in atom type

Hi,
I am simulating the pouring of particles in a container, but I got the error message
ERROR: Atom types must start from 1 for granular simulations
I used only one atom type but still getting this error. Can anyone tell why I am getting this error. Please find the input file below for reference

units lj
atom_style granular
atom_modify map array

boundary m m m
newton off
echo both
communicate single vel yes

region cyl1 cylinder z 0 0 5 0 10 side in units box
region con cone z 0 0 2 5 -5 0 side in units box
region cyl2 cylinder z 0 0 2 -10 -5 side in units box
region hopper union 3 cyl1 con cyl2 side in units box

create_box 1 hopper

neighbor 0.2 bin
neigh_modify every 1 delay 0

pair_style gran/hooke/history 3 0
pair_coeff * *

timestep 0.00001

fix cyl1 all wall/gran/hooke/history 1 0 zcylinder 5 0.5
fix con all wall/gran/hooke/history 1 0 zcone -5 0 2 5 0.5
fix cyl2 all wall/gran/hooke/history 1 0 zcylinder 2 0.5
fix bottom all wall/gran/hooke/history 1 0 zplane -10 NULL 0.5

fix p1 all property/global youngsModulus peratomtype 3.5e6
fix p2 all property/global poissonsRatio peratomtype 0.25
fix p3 all property/global coefficientRestitution peratomtypepair 1 0.6
fix p4 all property/global coefficientFriction peratomtypepair 1 0.5

fix g all gravity 1.0 vector 0 0 -1.0

fix pts1 all particletemplate/sphere 1 atom_type 1 density constant 3300 radius constant 0.5
fix pts2 all particletemplate/sphere 1 atom_type 1 density constant 2300 radius constant 0.5
fix pdd all particledistribution/discrete 1. 2 pts1 0.5 pts2 0.5

group nve_group region hopper
fix ins nve_group pour/dev nparticles 1000 1 distributiontemplate pdd vol 0.5 1000 massflowrate 1500.0 vel uniform 0. 0. 0. 0. -1.0 region cyl1

fix intg nve_group nve/sphere

compute 1 all erotate/sphere
thermo_style custom step atoms ke c_1 vol
thermo 1000
thermo_modify lost warn norm no

run 10000
unfix ins