This Google Analytics API error indicates that the security token for the account you are using has failed. Normally the security tokens are auto-renewed, but if you changed the account password or otherwise changed your security settings, the renewal can also fail.
To fix this error, open the Account wizard for the connector, select the account and click the Refresh Login button.
Older versions of the connector did not have a Refresh Login button, so in those cases, select the account in the list, click Delete Account, then enter the exact same reference name and click the Add Account button.