An Office 365 SharePoint Platform uses App-Only Authentication. The following error occurs when attempting to access the Platform from InfoBurst:
Logon to Site failed :: Token request failed
This error means the Client ID and Client Secret have expired. A Client Secret expires after 12 months by default. Upon expiry a new Client ID and Client Secret must be generated, access granted to the appropriate site collection(s), and the Client ID and Client Secret update in InfoBurst. A Client ID and Secret may be issued for up to three years. Consult your SharePoint administrator.