Make a Managed Visualforce Page show Header and Sidebar
Let’s say you’ve installed some managed package to your org and there’s a visualforce page in this package that doesn’t include header and sidebar . You need to redirect your users to this visualforce page, but the page breaks the look and feel by hiding the Salesforce header and sidebar. You can’t access or change the managed package’s code, so what else can you do?
Try creating a new visualforce page that will host the managed page within an
iframe. Your new page will make sure that header and sidebar are displayed.
If you need to send any parameters to the managed page, simply change the
src to include the required parameters. That’s it, I hope this helps someone.