Regarding read_restart

I am trying to use read_restart but I am getting an error saying atoms lost. I had initially run the simulation uptill 1500000 nd now want to run it upto 1600000. I am not very sure and how to use the read_restart command.
Any help would be appreciated. Kindly find the input and outputfile below.

# 3-d LJ flow simulation

#units lj
dimension 3
boundary p s p

#atom_style atomic
neighbor 0.3 bin
neigh_modify delay 1

# create geometry

read_restart restart.1500000.equil

#region simulation_box block 0.0 11.95 0.0 56.2 0.0 1204.14 units box #<<<<< CHNAGE DIMENSION CORRSPONDING TO PENETRATION DEPTH
#create_box 3 simulation_box

region fluid block INF INF 2.94 52.96 INF INF units box #<<<<< CHNAGE DIMENSION CORRSPONDING TO PENETRATION DEPTH
region btm_wall block INF INF INF 1.5 INF INF units box
region top_wall block INF INF 54.40 INF INF INF units box #<<<<< CHNAGE DIMENSION CORRSPONDING TO PENETRATION DEPTH

lattice fcc 0.81 orient x 1 1 -2 orient y 1 1 1 orient z 1 -1 0
#create_atoms 1 region fluid units box
lattice fcc 0.81 orient x -1 1 0 orient y 1 1 1 orient z 1 1 -2
#create_atoms 2 region btm_wall units box
#create_atoms 3 region top_wall units box

#mass 1 1.0
#mass 2 1.0
#mass 3 1.0

# LJ potentials

pair_style lj/cut 2.2
pair_coeff * * 1.0 1.0
pair_coeff 1 2*3 0.75 1.0
pair_modify shift yes

# define groups

group lower region btm_wall
group upper region top_wall
group boundary union lower upper
group flow subtract all boundary

set group flow type 1
set group lower type 2
set group upper type 3

# initial velocities

compute mobile flow temp
velocity flow create 1.10 482748 temp mobile units box
thermo_modify temp mobile

# thermostating

compute mobile_thermo all temp/partial 0 0 1
fix 2 all langevin 1.10 1.10 1.0 699483
fix 1 all nve
fix_modify 2 temp mobile_thermo
thermo_modify temp mobile_thermo

# Couette flow

velocity lower set 0.0 0.0 0.0 units box
#velocity upper set 1.0 0.0 0.0 units box
fix 8 upper move wiggle 4.0 0.0 0.0 80.0 units box #<<<<< CHANGE AMPLITUDE AND TIMEPERIOD
fix 3 boundary setforce 0.0 0.0 0.0

variable pxy equal pxy

region fix_fluid block INF INF 1.5 54.40 INF INF units box #<<<<< CHANGE DIMENSION CORRSPONDING TO PENETRATION DEPTH

fix 5 flow ave/spatial 40000 30 1600000 x center 11.95 z center 1204.14 y 54.4 0.25 vx region fix_fluid file vel_fb.profile units box #<<<<<CHANGE TIMESTEP FOR AVG. O/P CORRESPONDING TO TIMEPERIOD AND DIMENSION CORRSPONDING TO PENETRATION DEPTH
#fix 6 all ave/correlate 1 50000 50000 v_pxy type auto file pres_fb.dat
#fix 6 all ave/time 1 50000 50000 v_pxy file pres_fb.dat

# Run

timestep 0.002
thermo 10000
#thermo_style custom step temp evdwl ecoul epair ebond edihed eimp eangle emol etotal
#thermo_style custom step temp etotal c_mobile_thermo v_pxy

#dump 1 all atom 10 dump.flow
#dump 2 boundary custom 1000 dump.flow2 ys vx

#restart 500000 restart.*.equil

run 1600000

You're not losting atoms when you read the restart file,
but when you restart dynamics. This warning is bad:

WARNING: One or more atoms are time integrated more than once

Figure out why you are getting it and your problem will
likely go away.

Steve