Unexpected load/store type

I got following error message when I added cache directive as copied below. I wonder what does it mean by “Unexpected load/store type”?

*** Error message ****
PGF90-W-0155-Compiler failed to translate accelerator region (see -Minfo messages): Unexpected load/store type (dg_kernel.kernels.cache.f90: 62)

**** Source code *******

Real(Kind=double), Dimension(nx*nx,nelem) :: flx,fly
!$acc data copy(flx,fly) create(grad) copyin(gw,der,delta) 
      do it=1,nit
!$acc kernels
!$acc loop gang(ngangs) vector(neblk)
      do ie=1,nelem
!$acc loop vector(npts)
         do ii=1,npts
            k=MODULO(ii-1,nx) + 1
            s2 = zero
!$acc cache (flx(:,ie),fly(:,ie))

Hi Youngsung,

Most likely this is a compiler error. Can you please send a reproducing example to PGI Customer Service (trs@pgroup.com)?