Why can't I sync twitter on my Galaxy S3?????

I go into the app, and it asks "Authorize SNS to use your account?" and I click "Allow". And it says "Unable to complete the action." I've tried everything. I've uninstalled and reinstalled the app. I've signed in and out of my account. I've made a samsung account. I've made sure Auto sync data is enabled in Data usage. I've made sure sync data is enabled in the app. Nothing works! It still refuses to sync. What can I do to make it work?!?!? Please, someone help!!!!

you might have 2 way authentication activated. go to the site and fix that and then try might solve the problem.

I don't think I do. I went into Security and Privacy in my settings and I don't have the "login verification" box checked.