From Forum Nokia Wiki

ID	KIS000186	Creation date	February 3, 2005
Platform	S60 2nd Edition, Feature Pack 1 Series 80 2nd Edition	Devices	Nokia 7610, Nokia 6260, Nokia 6620, Nokia 3230, Nokia 6670 Nokia 9300, Nokia 9500
Category		Subcategory

Keywords (APIs, classes, methods, functions):

Overview

This option is ignored. In other words, the file is not deleted.

Description

The PKG file which is used to create the installation (SIS) file has several options for treating files during installation and uninstallation. FILENULL allows defining files that are created by the application and need to be deleted during uninstallation. However, this does not work in the devices mentioned above.
Due to this problem in uninstallation, the file is not removed.

How to reproduce

Use the FILENULL option in the PKG file.

Solution

There are two ways to implement a workaround. Instead of using the FILENULL option, it is possible to:
1) Use a zero-sized ’dummy’ file to create these files already during installation. For example:
; creates a zero-sized configuration file
; application will write to this file when run the first time
"dummy" - "c:\system\data\myapplication.ini"
Important: Make sure that your application will correctly handle the situation where the opened file has a zero length.
Or,
2) Create a simple program to be run at removal time. This program will then manually delete the application-created files from the file system. Running the program automatically during removal is possible by defining the FILERUN (FR), RUNREMOVE (RR), and RUNWAITEND (RW) options in the .pkg file. For example:
; run our own uninstaller exe during removal
"uninst.exe" - "!:\system\apps\myapp\uninst.exe", FR, RR, RW
Example implementation of a simple uninstaller program:
Uninst.zip