If you are looking at this in trace, you can expand the failed action to see the details.
The same applies if you are looking at the errors in the connectors part of the UDH UI. You can click there to see the details of the failures. See screenshots attached.
If the details do not help you identify the issue, I'd suggest you raise a ticket with firstname.lastname@example.org, telling them the account and profile and details of the error you are seeing.