I cannot log in fb account

Hello, I am getting  "you need the official whatsapp to use this account android" when i try to login in WhatsApp using my number. I downloaded WhatsApp from official Play Store. I even tried downloading apk from official website and installing. I even formatted the phone and tried again. Still i am getting same results. I tried contacting WhatsApp support but they are saying to use official WhatsApp. If someone know how to resolve please help me out. 

I logged out of Facebook on every device, because I changed my password. I also pressed X on every recognisable device, just to make sure, that I haven't left Facebook somewhere logged in. And I have had set two factor authentication on. Now I can't log in, because it asks me for 6 digits code, which can only be retrieved when logged in.  I am using same phone and same 2 computers to log in, that I have used to be logged in for many years, but it still can't log in.  I sent my passport photo to Facebook support, but it only changed log in email, which doesn't help, because it still asks me to enter 6 digits code out of code generator. Please advise what I should do? I am logged out for a...

I never use to login to chrome and had lots and lots of bookmarks. Then I logged in with my regular google account and there are no bookmarks. There's no option to "log out" that I see, so I can see them again. Just an option to switch to a guest account. No bookmarks there. I turned on sync but don't think that's it. What am I syncing it from if I was never logged in? Any clue how to get all my bookmarks back?

Thank you!
Beau

Hello,
I am trying to log in with my email id and the password , but since morning I get only one response and that is

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Can any one please help me as to why is this happpening.

Best Regards
shazneenConfiguration: Windows Vista Safari 532.0

Hi! I’m struggling so so much with this, and it’s driving me mad. Last night I used a third-party app to look at my insights and stuff, but soon after discovered that such apps aren’t always trustworthy, so I logged out, and uninstalled it. I’ve always been logged into my account from my phone and iPad, but ever since last night, I get logged out of one device if I log into the other. It’s never been like this. I was always able to be logged into the account from both devices simultaneously, no problems whatsoever. After I uninstalled the Instagram followers analysis app I changed my password in fear that the app had access to my account. I’ve changed my password again since then, am able to...