Getting error when fulfill the order in Mobile Client(Unified User Interface)

Hi,

I am getting following error when I fulfill the order in Mobile Client(Unified User Interface). However, it is working fine Web.
1- We have created a plugin which verify few things before SalesOrder get fulfilled or canceled.
2- We have created a plugin which enter data to other entities after SalesOrder get fulfilled or canceled.

Error Message:"This message can not be used to set the state of SalesOrder to Fulfilled. In order to set state of SalesOrder to Fulfilled, use the FulfillSalesOrderRequest Request message instead."

Version: MS Dynamics 365, v9.0

Please suggest