use EnVisage

update ScenarioDetail set WeekEndingDate = null --these are index blockers, probably migrated from Projections
where WeekEndingDate = '1/1/1900'
go

CREATE UNIQUE NONCLUSTERED INDEX DF_Scenario_Detail_Unique
ON ScenarioDetail(ParentId, ExpenditureCategoryId, WeekEndingDate)
WHERE WeekEndingDate IS NOT NULL
GO