When using the Dropdown Toolbar that comes with Framework 6.1, or any variants on that Dropdown Toolbar, make sure that you don't take away all of the Navigations. At least one of Horizontal Navigation or Vertical Navigation must be selected, or else the portal will throw a yellow-screen error that will make it unusable for that person.
The solution if that happens is to reassign the user either a different toolbar or one of the two types of navigations. OR
Add the attached Layout to the Layouts Folder (after extracting) (inetpub/wwwroot/Production_Portal/Navigation Layouts/)
Assign the OnSemble Blue Empty Navigation to everyone you want to have Dropdown Toolbar with no Navigations.