Can't Login to Outlook.com "This account can't be used to access Outlook.com " error

"This account can't be used to access Outlook.com

You're currently signed in with an Office 365 email account, which can't be used with Outlook.com. Please click here to sign out of your Office 365 account, then use another Microsoft account to sign in to Outlook.com (for example, your hotmail.com, live.com, or msn.com account). "

Most likely cause is the email address/account you're using belongs to a educational institution, work or other big institution who pays Microsoft for the services. What has happened is they've switched your account from Outlook to a Office365 account, possibly without telling you.

Microsoft has stupidly put the above error message which isn't immediately obvious what to do.

Fix:

1. Go to http://login.microsoftonline.com
2. Login
3. That's it

And no Microsoft can't put this URL in the error message above because it would make it too user friendly and easy to use/fix. It's more fun searching Google for a forum or blog like this right? .... 

An attempt to login to the mailbox via www.office365.com will result in a circle of purchase this and purchase that advertising instead.