field symbol error type any

Hi

I want to move one value to my field symbol it is showing error

The data object "<FS_WA>" has no structure and therefore no component called "ZPROVIDER". called "ZPROVIDER".

See below of my code and help me how to move the value.

FIELD-SYMBOLS : <fs_afvg_bt> TYPE ANY TABLE  ,  "OF AFVGB . " WITH HEADER LINE,

                              <fs_wa>      TYPE ANY ,

                              <fs_guid>  type afvgb-/***/cuguid .

     DATA : is_data TYPE /***/cafcu .

ASSIGN ('(SAPLCOBO)AFVG_BT[]')  TO <fs_afvg_bt>.

LOOP AT <fs_afvg_bt> ASSIGNING <fs_wa>.

       ASSIGN COMPONENT '/***/CUGUID' OF STRUCTURE <FS_WA> TO <FS_GUID> .

       CALL FUNCTION '/***/CUINST_BT_READ_SINGLE'

         EXPORTING

           is_cuguid     = <FS_GUID>

          IMPORTING

           es_cafcu      = is_data

         EXCEPTIONS

           no_input_data = 1

           not_found     = 2

           OTHERS        = 3.

        IF sy-subrc <> 0.

* Implement suitable error handling here

       ENDIF.

Here i want to move some data getting from ls_data to <fs_wa>. i tried below two statements but getting error.

       move is_data-zprovider to <fs_wa>-zprovider.

       <fs_wa>-zprovider. = is_data-zprovider .

     ENDLOOP.