Are you connected to the internet? Haha, seriously however, are you?
Assuming you have the best login email and also password (as well as you're connected to the web) there's a couple of points that could be creating your troubles:
Trouble With Facebook Login
Are you obtaining an error message? If so, examine the Facebook help page for descriptions and also fixes to known problems.
Ensure you don't have any type of expansions or antivirus programs running that are obstructing Facebook.
Have you tried getting rid of the app's cache? Go to Setups > Apps > Facebook > Clear Cache. If this does not work you can try clearing data as well and as a last resource uninstalling and also re-installing the application entirely.
Did you join your contact number? Ensure you enter the nation code also when visiting.
If the app is telling you to upgrade your email address, this is most likely since your email web server is classifying your Facebook emails as spam.
If you have actually recently registered for Facebook you may require to verify your account first. If you have actually just recently transformed your password, ensure you're trying to log in with the brand-new password and also not the old one.
If you're visiting through a browser, make sure you have cookies enabled and that facebook.com is added to your list of secure websites.
Make sure you have one of the most recent variation of the Facebook app for Android.