Whatsapp 2.11.561 keeps on asking to updateand i did

install whatsapp on you pc and then put your number in where ther ask for the number

whatsapp is free but u have to pay 0.99$ per year for it

Hello, it depend where you want to install whatsapp. If it's in your computer; You'll need to use an emulator and the apk file of whatsapp.
?Source: http://www.technotup.com/download-whatsapp-for-pc-windows-xp78/

I am not saying it is definitely Malicious, it hasn't been figured out yet, so delete them from contacts and clear cookies.

(Somebody else tried blocking him, then they used a different number!)

In my opinion it is Spam and may be Malicious.

Tried changing automatic time update to off and setting time, didn't help. Eventually, figured out a simple solution.
Firstly, see that you are connected to internet. Go to play store and get whatsapp updated. Or get Whatsapp v 2.9.5196 or higher. Then, go to app drawer and open whatsapp messenger. Accept terms and conditions. It will then ask you to enter your mobile number. Just type that in and thats it. If you are an existing user, your account will get synced automatically, or else create a new account.
This error happens usually when you change time zone or if you end up with an outdated whatsapp by changing ROM, like what happened to me.

They might be experiencing a problem right now on their new update. Just wait and try again.