2735793 - STRG_ILLEGAL_PAR: Value '25' not permitted for parameter 'FORMAT'

Shortdump STRG_ILLEGAL_PAR happens in the system:

Category                      ABAP programming error   
Runtime Errors             STRG_ILLEGAL_PAR      
Except.                        CX_SY_STRG_PAR_VAL      
ABAP Program              CL_DD_AREA====================CP      
Application Component BC-CI-DYD      

Short Text

  Value '25' not permitted for parameter 'FORMAT' <<<<TRAN

What happened?

  The invalid value '25' was passed to parameter 'FORMAT' of the function 'ESCAPE'. 

Source Code Extract   

  |   28|  ENDIF.       
  |>>>>>|  act_value = escape( val    = opt-value                            
  |   30|                      format = 25 ). " cl_abap_format=>e_xss_ml_7b  

SAP KERNEL 6.40 < SP415  
SAP KERNEL 7.20 < SP320 
SAP KERNEL 7.21 < SP029

STRG_ILLEGAL_PAR, CX_SY_STRG_PAR_VAL, CL_DD_FORM_AREA===============CP , CL_DD_FORM_AREA===============CM003, ADD_SELECT_ELEMENT, kernel , KBA , BC-ABA-LA , Syntax, Compiler, Runtime , Problem