iforrtl: severe (67): input statement requires too much data, unit 20 error

Hi Support,

While I am executing my fortran program which reads huge Unformatted data, I am getting following error.

iitmlogin3:/hpcs/bipink/LES/cloud_phy $ ./a.out 

forrtl: severe (67): input statement requires too much data, unit 20, file /hpcs/bipink/LES/cloud_phy/mixing_data

Image              PC                Routine            Line        Source             

a.out              00000000004060D9  Unknown               Unknown  Unknown

a.out              000000000041CB46  Unknown               Unknown  Unknown

a.out              00000000004034BE  Unknown               Unknown  Unknown

a.out              000000000040329E  Unknown               Unknown  Unknown

libc.so.6          00000038AE61ED5D  Unknown               Unknown  Unknown

a.out              00000000004031A9  Unknown               Unknown  Unknown

iitmlogin3:/hpcs/bipink/LES/cloud_phy $

Following is part of my program:

IMPLICIT NONE

   REAL(KIND=8)    :: e, diss, ens, mse, susa, q, pt, simulated_time, id, x, y, z, radius
   INTEGER(KIND=4) :: number_of_particles, n, unit

   unit = 20
   OPEN(unit,file='mixing_data',status='old',action='read',form='unformatted')
   DO
      READ(unit,END=5) e, diss, ens, mse, susa, q, pt, simulated_time, number_of_particles
      DO  n = 1, number_of_particles
         READ(unit,END=5) id, x, y, z, radius
      END DO
   END DO
5   CLOSE(unit)

Thanks and regards,

Sachin