Can you be more specific as to what "layout tools" have gone missing for you?
Are these the tools that appear in a row across the top of the screen when you click the Aa button at top right?
The missing tools icons appear in Edit Layout mode, starting with create Text box, and many others (about 10) that include insert field, portal, etc.
Aha! Found the problem - it is restored in View / Customize Toolbar when in Edit Layout mode.
These icons will disappear if the window is "too small". They should reappear if you resize your window larger--perhaps increasing your monitor resolution to do so.