3168901 - Dump GETWA_NOT_ASSIGNED with CL_FPM_BICS_GRID_UIBB_ASSIST==CP in Bex Query

Below error happens during process (e.g. right click a column to open context menu) on FPM webdynpro of Bex Query:

500 Internal Server Error
Field symbol has not been assigned yet.

The ST22 dump generates at the same time:

Category               ABAP programming error
Runtime Errors         GETWA_NOT_ASSIGNED
ABAP Program           CL_FPM_BICS_GRID_UIBB_ASSIST==CP
Application Component  BW-RUI-FPM
Date and Time          ...

 Short Text
     Field symbol has not been assigned yet.

 What happened?
     Error in the ABAP application program.

     The current ABAP program "CL_FPM_BICS_GRID_UIBB_ASSIST==CP" had to be
      terminated because it found a
     statement that could not be executed.

SAP_BW 754

500 Internal Server Error, bex, FPM, analytic Grid, FPM_BICS_OVP, Field symbol has not been assigned yet, GETWA_NOT_ASSIGNED, CL_FPM_BICS_GRID_UIBB_ASSIST==CP, drilldown, Add Attribute, Select Attributes , KBA , BW-RUI-FPM , FPM Analytical GUIBB , Problem