I get the following error when trying to validate and sync my newly created External data source for SharePoint Online in Salesforce: "Status An unknown error occurred while accessing Files Connect."
Also, if I try to access SharePoint Online from the "External Files" in "Select a File to Attach", I get the following error after it has loaded: "We couldn't log you in to Sharepoint Online. Contact your salesforce.com administrator.".
If I try to upload a document from the Files tab and selects the SharePoint Online I get: "An unknown error occurred while accessing Files Connect."
I have set up "Authentication Settings for External Systems" and it says that I'm authenticated.
Also, I have granted access to the Documents App when creating the External data Source, and there everything worked, I accepted and it redirected me correctly after selecting "Start Authentication Flow on save".
I have looked over the only suggested solution I foound on this: Suggested Solution, but it didn't help. I have the following permissions:
<AppPermissionRequests>
<AppPermissionRequest Scope="http://sharepoint/content/sitecollection/web" Right="Read"/>
</AppPermissionRequests>
So does anyone have any idea what I could be missing or where it might be an error?