calling mexw64 function second time goes wrong

When I call my myPET3copy.mexw64 function, the first time goes well but the second time goes wrong.

>> input=[.42,.1,400.,.085,6000,.675,1500.,.125,.125,300.,14.,.54,2.57,.33,.0003];
>> output=myPET3copy(input)

output =

   1.0e+05 *

    0.0600    0.0000    0.0150    0.0518    0.0000    1.1861    0.0005    0.0000

>> output=myPET3copy(input)

output =

        6002         NaN        1500         NaN         NaN         NaN         NaN         NaN

following is my mexfunction

        #include "fintrf.h"
        subroutine mexFunction(nlhs,plhs,nrhs,prhs)
        implicit none
    
        mwPointer plhs(*),prhs(*)
        integer*4 nlhs,nrhs
        mwPointer mxGetPr
        mwPointer mxCreateDoubleMatrix
        !integer*4 mxIsNumeric
        mwPointer mxGetM,mxGetN
        mwPointer input_ptr,output_ptr
        mwPointer mrows,ncols
        mwSize size
        COMMON/PAR/INPUT(15),OUTPUT(8)
        real(kind=8) INPUT,OUTPUT
        mwSize :: ONE=1,EIGHT=8
        integer :: ComplexFlag=0
              
        mrows=mxGetM(prhs(1))
        ncols=mxGetN(prhs(1))
        size=mrows*ncols
        input_ptr=mxGetPr(prhs(1))
        call mxCopyPtrToReal8(input_ptr,INPUT,size)
        plhs(1)=mxCreateDoubleMatrix(ONE,EIGHT,ComplexFlag)
        output_ptr=mxGetPr(plhs(1))

          call myPET3()
 
        call mxCopyReal8ToPtr(output,output_ptr,EIGHT)
    
        return
        end

Why could it be like this?