Occasionally Access Tokens expire and get invalided by Facebook and Google as part of their normal security practices. When this happens you need to login again to re-authenticate the connection and get an updated/valid access token.
You will receive a notification message in your inbox to alert you that an account is Invalid and therefore needs to be re-authenticated.
Once this happens go to the "Accounts" page in
Senalysis. You will see a Red Warning Status next to the account(s) that need to be re-authenticated. Follow the instructions below.