After upgrading to the latest version of Commerce the "Commerce" option in the top menu does not show any links when clicked. I have checked the code and it looks like the section "global_Commerce_sub" is not rendered on the page. Any ide of what could be wrong/missing?
Could something have happened with the groups the user is a member of during the upgrade? Because menu options will be hidden if you are not a member of specific groups. Either "CommerceAdmins" to get access to all commerce view, or "CatalogManagers" or "CommerceSettingsAdmins" for access to specific views.
Additional comment to Per's answer: also make sure that EPiServer.Commerce.UI and EPiServer.Commerce.UI.ManagerIntegration nuget packages are properly upgraded.