Let's look at a business scenario. Helina Jolly is working as a system administrator in Universal Containers. She has developed a Flow, that is, Create Leads in Chapter 3, Manipulating Records in Visual Workflow, and embedded it into the custom button. She has received several e-mails from users saying that they are getting Insufficient Privileges Errors when they click on the Create Lead button, as shown in the following screenshot:

If a system administrator embeds a Flow into the custom button or link, then to run a Flow, the user must have either run Flow system permission under profile or the Force.com Flow User feature license selected in the user record.