Problem with trigger program - pointer problem

[Tomasz Skorża <t.skorza@xxxxxxxxxxx>]

Hi

If you have any idea please help - I don't know now what I did wrong ...
I have an RPGLE program which is trigger program ... monitor every add, change and delete actions 
and write it to audit file.
Program worked correct.
But than, I added some modification - after writing to audit file I do some additional very small 
action, check one external file and write to another one file.

And now when I call the program I get message:

CPF8E17
Pointer not set for location referenced.

then
RNQ0222
Pointer or parameter error (C G D F).

Message . . . . :   Pointer or parameter error (C G D F).
Cause . . . . . :   RPG procedure P55400TRG in program PRTRG/P55400TRG at
  statement 452 had an error due to a pointer not being correctly set. The
  cause of the error is most likely one of the following:
    -- A basing pointer was not set.
    -- A procedure pointer was not set.
    -- The pointer was set, but the object it referenced has been destroyed.
    -- A parameter was not passed to the program containing the procedure.
    -- A parameter was not passed to the procedure by its caller within the
  program.
    -- A pointer offset was greater than the size of the space the pointer was
  pointing to.

then RNX1024
An error in the trigger program was detected after WRITE on file F55400.

I read many web pages about this problem and not exactly sure what  cause the problem?

In my additional code I didn't add any call statement, I didn't change any other/original call 
statements, so it is rather not problem with parameters ...

So what is the problem?

Regards

Tomek