Here's the reply from Tapatalk
Try again, Jayeley didn't mention which setting but i'm guessing it's the Allow Guest one, i've changed that so see what happens.
If this fails there are only a few other settings that can be changed and we'll get there eventually
Edit: Just thought, I don't understand why you are having a problem?? what's different with your account than others who can log in no problem, you are using an iPhone?