How to register a client name with Google?

Question

I have two applications which access my users' calendars via a service account. Until today everything was working fine and out of a sudden one of the app cannot get a grant token. I read that this may be due to the same service account being used simultaneously (which was the case for a year but never mind) so I decided to

• create a second service account
• and authorize it to access the calendars

I created the service account in the Google Developers Console -> API Manager -> Credentials.

The console now looks like this:

Service account client 1 is the original service account which was working for both apps and now works for one of them only. The ga... account is the newly created one.

In order to get the ClientID I went (on the same page) to "Manage service accounts" and I get this:

The newly created account does not offer the possibility to check its ClientID. Why?

The ClientID is also available in the JSON file downloaded upon creation. I extracted it from there and tried to authorize the access in my GApps Security console:

As you can see it was refused.

What part did I miss when creating this second account?

Answer 1

Found it:

and after checking the checkbox below both accounts look the same, the ClientID is available and it can be authorized in the GApps console.