CopyPlanSetup fails when attempting to copy a plan that is approved

[tkstevens]

Given a Treatment Approved sourcePlan in course sourceCourse, a new plan can be created with newPlan=sourceCourse.CopyPlanSetup(sourcePlan). However, upon app.SaveModifications() an error is produced that mentions "tU_PlanSetup_VaBusinessLogic, Line 694: PlanSetup is approved: Cannot UPDATE PlanSetup. PlanSetupSer: 549944", where 549944 is the Ser of the sourcePlan (and no modifications are being asked of this plan). The workflow runs fine when copying an unapproved plan.