Trying to get a simple connection stood up to my SharePoint Online site in TDP 5.5. Getting an error 'Invalid data source definition: SharePoint: failed to get binary security token, caused by '. I was under the impression support for SharePoint Online would be included in TDP 5.5.
Welcome to the Toad Data Point forum, Derek13.
TDP 5.x does support Sharepoint Online connections. Assuming that you've confirmed your credentials with your Sharepoint admin, I wonder if this Knowledge Base Article offers some resolution?
It may be that your Sharepoint online is used MFA (Multi-Factor Authentication) which we are not supporting yet but hope to in the first release next year