Hi Mayank,
This can haapen if your DI API uses a different License Server than the B1 application.
Compare the License Server settings in both b1-local-machines.xml files. TheB1 application is under C:\program files (x86)\SAP\Sap Business One\Conf and the other is under C:\program files (x86)\SAP\Sap DI API\Conf.
Note that the path C:\program files (x86) can be different in your computer.
Beni.