Fix your iPhone Facebook app login problems!
If you are getting an error every time you try to login to the Facebook app on your iPhone, try this solution. Go to http://www.facebook.com/iphone On the left-hand side (you may need to scroll down) click "Remove app" Now try logging in again on your iPhone. Source I found the solution here: http://goo.gl/LPYEu So what caused the problem?.. Not exactly sure, but this started happening right after I update my Facebook security setting. I had turned on HTTPS and had activated alerts for when a new computer or mobile device logged in to my account. One of these settings must have caused it.