If you update your security settings on Twitter such as your email address or password, you will need to reconnect any related Twitter Services before you're able to post again.
Please remember to log out of Twitter.com to ensure you are reconnecting the correct Twitter account.
To reconnect a Twitter service, please do as follows:
1. Go to Services > My Services
2. Locate the Twitter Service in question that needs reconnecting and click Edit icon.
3. Click Reconnect To Twitter
4. Enter your login details and click Authorise App
5. IMPORTANT: Click Update Account to finish the reconnection process
Why not go through our Troubleshooting Issues Checklist?