Coinbase, can not connect: fetching your balance amount from the exchange so you would need to enable that option if available

[MichaelUray]

It ends up with the following error message if I try to add a coinbase account as Exchange External Service Data:

"Could not connect with current settings. Transmuter tests against fetching your balance amount from the exchange so you would need to enable that option if available"

The API key has all permissions and it shows that it is activated (I had not to wait for 48h as I did read in the Internet).

btcTransmuter always reports the same message, even when I remove the API key.
Where can I get more detailed logs about that what causes the error?