BE CAREFUL,
Some add-ons are causing menu items not to be displayed. No options to navigate World Menu and select ‘Fly’
I suspect it’s an add-on that adds an option to the ‘ToolBar’ such as ShiftStats or ‘Pushback Helper’ etc.
Disabling community folder items fixes problem. This type of problem is expected until developers update their software. Don’t panic if you find the same problem. 
Image: Menu items missing caused by third-party addon.
Here is the fix and the add-on causing the problem…
Charles.