Hi @Rahul_Arora,
Are you sure you’re looking at your PHP error log, and not e.g. your Apache error log (which may or may not be the same thing)?
I see you’ve also asked on StackOverflow – there’s a recommendation there. Generally speaking it’s better to post in one place (and I’d recommend this forum over StackOverflow, just because there are more OJS users here). Posting in multiple places divides the conversation.
Regards,
Alec Smecher
Public Knowledge Project Team