Notice Period Validation Whenever Grade Change in Assignmentpage

Summary:

HI Team, We want to put a validation in the system that whenever a user is doing an action on employee assignment like Transfer, promotion, Assignment change etc, The system should validate the Notice Period based on LE and Grade. Our Notice period is dependent on LE and Grade and ACR is to be created for validation based on LE and Grade

Content (please ensure you mask any confidential information):

Customer Name:Al Tayer Group LLC.

Approved Use Case No: 7

I have build the code and validation is also happening but facing an issue in JAva.null pointer exception during Assignment change action - grade change.