the argument 'null' cannot be interpreted as a number - DTP issue

Hi Gurus,

I am facing an issue while running the DTP.

Below is the error.

When I see long text, it says the error is on line 1620 of program.

So, I go to the program and try correcting the NULL value by inserting a code but it is still not fixed.

the variable type of kascnetva is CURR and mgtvalue2 is char. I tried to include the code with (IS INITIAL) but still not working. Anything else that can be tried ?

Thanks in advance.