Are you connected to the net? Haha, seriously though, are you?
Thinking you have the ideal login email and password (and you're attached to the internet) there's a few points that may be creating your issues:
I Can't Login My Facebook Account
Are you getting an error message? If so, check the Facebook help page for descriptions and fixes to recognized problems.
Ensure you do not have any kind of expansions or antivirus programs running that are blocking Facebook.
Have you attempted getting rid of the app's cache? Go to Settings > Apps > Facebook > Clear Cache. If this doesn't function you can try clearing up information also and also as a last resource uninstalling as well as re-installing the application entirely.
Did you sign up with your telephone number? Make certain you type in the nation code also when logging in.
If the application is informing you to upgrade your e-mail address, this is more than likely since your e-mail server is labeling your Facebook e-mails as spam.
If you've lately enrolled in Facebook you may require to confirm your account initially. If you've recently changed your password, make sure you're attempting to visit with the new password and not the old one.
If you're logging in using an internet browser, make sure you have cookies allowed which facebook.com is included in your listing of safe sites.
Ensure you have one of the most recent variation of the Facebook app for Android.
