I actually think there is no difference in the programs, I suspect the difference in the data.
Not talking about the data in the source file, I am talking about the existing info records. you might have created your recording with info records that are created at purchasing org level only, but in production you hit purchasing info records that are created at plant level or vica versa.
the usual root cause that something is different in DEV/QA versus PROD is a transport of a program change which is not yet released to PROD.
Maybe you can be clearer in your description of the environment situation.
you wrote "We had been using an for Info record change lsmw in production server since a year and it was working fine. But, it is stopping in the last screen ..."
Where did this run fine for a year? in production?
Did it just suddenly stop at the last screen? or was this a problem from the very beginning?
you wrote: And i have tried several times in PRD by creating new one once again
Are you allowed to create LSMW directly in PRD? or did you do it in DEV and transported it to PRD?
How is this transport done? with Export/Import or with a transport request?
What made you think to redevelop the LSMW?