Regression:- Server error is displaying after changing employee status.

1] Login to the application as a partner.
2] Change status of employee to terminated.
3] Login to a company with above employee , make sure no mode is set for employee. (i.e. employee should not eligible for NH or OE).
4] Add Spouse or Child.
5] Login to to application with partner and try to change status for that employee.

Actual Result:
Server error is displaying.
Expected Result:
Server error should not be display.
Refer attached error log for more details.

Please note :
If this user is eligible for NH or OE, server error is displaying after adding Spouse or child.