HSDL gives an error corresponding date effective record in the Assignment is missing in Workterms

Dear ,

I have an hsdl for grade change when i change its gives me an error

The corresponding date effective record in the Assignment for date 2023-02-07, action GRADE_CHG, and effective sequence 1 is missing for the WorkTerms.

i dont know why it is even if i change action code GRADE_CHG to any other code its give me same error .

Can any guide me what is the issue and how to resolve

Thanks