Are you linked to the web? Haha, seriously however, are you?
Assuming you have the best login email and also password (and also you're attached to the net) there's a couple of points that might be creating your troubles:
Can't Log Into Facebook
Are you obtaining an error message? If so, examine the Facebook help page for explanations as well as fixes to recognized problems.
Make sure you don't have any extensions or antivirus programs running that are blocking Facebook.
Have you tried getting rid of the app's cache? Go to Settings > Applications > Facebook > Clear Cache. If this does not function you can attempt cleaning data as well and as a last option uninstalling and re-installing the application entirely.
Did you sign up with your contact number? See to it you enter the country code also when logging in.
If the app is telling you to upgrade your e-mail address, this is probably because your email server is labeling your Facebook e-mails as spam.
If you've recently registered for Facebook you may require to validate your account first. If you've recently altered your password, make certain you're trying to log in with the new password as well as not the old one.
If you're logging in via a web browser, make certain you have cookies enabled which facebook.com is added to your listing of secure websites.
See to it you have the most current variation of the Facebook app for Android.
