Pressing the alt key or F10 will reveal hidden menu bars momentarily. From the menu bar select View-Toolbars and turn the missing toolbars back on.

You are correct but it is only a one-off fix. The toolbar disappears again after I click it.

How do I retain and use the toolbar?

Did you follow the entire instructions?

View-Toolbar-Composition Toolbar

This should turn the composition toolbar on to stay.

Thank you for latest email but I am unable to locate 'Toolbar Composition' on the 'View' drop down...only 'Customize'.

Do you know what I am doing wrong?

I have no idea what you are doing.

Open a Write Window Do you have a Menu Bar with File, Edit, View etc? If not press the alt key.

From the Menu Bar select View-Toolbars-Composition Toolbars

See image.