“Add Existing Package” Quirk

Kenneth Fisher points out an “interesting” quirk with SQL Server Data Tools when you try to add an existing package under certain circumstances:

That SSIS change just won’t stick! There is a new business requirement, so now you have to change an existing SSIS package. You opened up a new project, imported the package, and made your changes.

But the changes just aren’t showing up. You back and look again and sure enough, the changes you made are there. You run your job (or whatever) and still the change aren’t taking effect. So what happened?

Read on for the cause and the solution.