Why can't I log into my Facebook account to connect to Instagram?

[iMore Question]

I've been using Instagram in my iPhone 5s for a couple of years or more and I've never had any trouble but last month or so, Instagram asked me to log into my Facebook account to share my pictures there (as I've always have shared them) so it sent me to the Facebook link in Safari. But when I try to log into my account I get stuck in the logging in screen and can't log in. It seems like it's logging in but after it charges, I'm back at the same logging in page. I tried deleting Instagram and Facebook from my iPhone but I still have the problem. And I checked if it was just when I tried to log in to connect my Instagram account to the Facebook one but if I try to log into Facebook through Safari I have the same problem.

 

[Just_Me_D]

I can only assume the problem lies on the side of Facebook, and not the device or the app. Can you login via a computer?

 

[Grabber5.0]

I got logged out on my Lumia a day or so ago and couldn't log back in.. I blamed Windows.. Maybe it's something else then.

 

[Ledsteplin]

I haven't had any problems with Facebook. Have you signed in to Facebook in your phone's Settings?