If you update your login credentials such as email or password you will be asked to reconnect your Facebook Services before you're able to post again.
Before you start reconnecting to your facebook page, please make sure you have logged out Facebook in your web browser.
To reconnect a Facebook service, please do the following:
1. Go to Services > My Services.
2. Locate the Facebook service that is no longer posting and click the Edit icon.
3. You may be asked to login again to your Facebook account if you're not logged on already. If you're logged on to the incorrect account, please use Switch Facebook User as per Point 5.
4. Check all the settings for the service are correct and select the Update Account button.
5. Or click Switch Facebook User to change user accounts.