Hello Pranab,
Please note that the Line item management CANNOT be deactivated, if open item management is activated in FS00.
Either you will need to deactivate both, or you can only deactivate Open item management. But you CANNOT deactivate only Line item management, when OIM is still checked.
You can only active or deactive open item management if the account balance is ZERO. Block the account for posting. to deactive line item.
I hope this OSS note is useful to fix your issue.
Note 31875 - G/L account line item management
Please revert us if you still face any issues.
Thanks & Regards,
Lakshmi S