SharePoint Online Connector

Hi All -

We are having difficulty connecting Workplace search and SharePoint Online. We have followed the docs, had multiple people verify the setup but we can not get the o365 authenticated. We get
Message: AADSTS50011: The reply URL specified in the request does not match the reply URLs configured for the application: 'b106c3af-d1fe-4588-b10c-3f0c49811ede'.

Would greatly appreciate any help.