I have the same problem. Playmemories Online menu is missing.
The Playmemories Home application is the latest 5.1.00.12260. Menu is missing on my both computers, running Windows 8.1 and Windows 10. Reinstalling doesn't help. Using another internet provider doesn't help, too. I tried the Settings initialization tool, nothing changed. And more, on my Macbook the Playmemories for Mac doesn't connect to my psn account, it shows the login box, says 'login successful' when I type the login and password in - and then nothing happens. No connection to psn at all.
And on my PS4 Playmemories works with my psn account as a charm. And on my Android phone it works, too.