Getting server error when adding new employee on softchoice company

Getting server error when adding new employee on Softchoice company.
tried on another company employee added successfully.
Getting same error when adding Spouse and child.
Spouse and Child Data is added in system But it terminate Health and dental EE only plan and Not enrolled in Health and dental Family plan.
Checked on confirmation statement and Enroll now screen.

refer attached screen and below error log:

ErrorID : 0
ErrorSource : ControllerAppTier.Save->WORKTERRAControllerAppTier.Save->EmployeeData.Save->EmployeeData.UpdateEmployeeProfile->EmployeeData.CreateUserForEmployee->CorePlanAllocation.CorePlanAllocationForOptimization->CorePlanAllocation.ActualCorePlanAllocation->EnrollmentBulkInsert.InsertUpdateEnrollmentInBulk_CorePlan->EnrollmentBulkInsert.ProcessDataForEnrollment_CorePlan->EnrollmentBulkInsert.GenrateEnrollmentInsertQueryString->RateCalculationForEnrollment.GetGenericRatesCalculation->RateCalculationForEnrollment.GetCostForLifeAndLTD->RateCalculationForEnrollment.GetLifeCostWithSubRatesAndOfferedAmount->RateCalculationForEnrollment.GetDefaultCostFromSubRate
ErrorMessage: Item has already been added. Key in dictionary: '1~5189~-1' Key being added: '1~5189~-1'
StackTrace: at WORKTERRA.Shared.WORKTERRAControllerAppTier.Save(WORKTERRAControllerWebTierEntity objWORKTERRAControllerWebTierEntity)
at WORKTERRA.ControllerAppTier.Save(Int32 intProjectsId, String strInput)
TargetSite: System.String Save(WORKTERRA.Shared.WORKTERRAControllerWebTierEntity)