forrtl: severe (36) error

[Deepa_J_1]

I have been using a model compiled with pgi compiler package in intel ifort compiler environment. The original pgi compiler "configure.user" file has the following lines.

SFC       = pgf90
FC        = mpif90
FOPTS     = -byteswapio -fastsse
FOPTS2    = -fastsse
FMCMODEL  = -mcmodel=medium
FFREE     = -Mfree
FFIXED    = -Mfixed


I changed the above lines for intel ifort as below.
 

SFC       = ifort -assume byterecl -mkl=parallel
FC        = mpiifort -assume byterecl -mkl=parallel
FOPTS     =-convert big_endian -O2
FOPTS2    =  -O2
FMCMODEL  = -mcmodel=medium -shared-intel
FFREE     =  -free
FFIXED    = -fixed
 

The error I am getting constantly is

forrtl: severe (36): attempt to access non-existent record, unit 11,
Image              PC                Routine            Line        Source
grd2ss             0000000000607783  Unknown               Unknown  Unknown
grd2ss             00000000006054C6  Unknown               Unknown  Unknown
grd2ss             000000000040E0FD  Unknown               Unknown  Unknown
grd2ss             000000000040428D  Unknown               Unknown  Unknown
grd2ss             0000000000403A56  Unknown               Unknown  Unknown
libc.so.6          00007F24DB18BCDD  Unknown               Unknown  Unknown
grd2ss             0000000000403949  Unknown               Unknown  Unknown
 

I understand that the source of error is from the below quoted lines from a Fortran script used in my model.

  iunit=11
  INQUIRE(IOLENGTH=iolen) iolen
  OPEN(iunit,FILE=filename,FORM='unformatted',ACCESS='direct',RECL=nij0*iolen)

  irec=1
  DO n=1,nv3d
    DO k=1,nlev
      READ(iunit,REC=irec) ((v3d(i,j,k,n),i=1,nlon),j=1,nlat)
      irec = irec + 1
    END DO
  END DO
Kindly suggest me what should I do to solve this issue? Any compiler flag modification can solve this problem?

[Steven_L_Intel1]

How big is the data file in bytes? What are the values of nij0 and iolen, and at which value of irec does the error occur? Does the error message name the correct data file?