LCS Diagnostic Tools - Failed to Invoke Diagnostik External Services

I just installed LCS System Diagnotic to get an overview of the functionality provided within the life cycle services. After the Installation process I started Diagnostics Services and got the following error message:
"Failed to Invoke Diagnostic External Services:  Keyset does not exist" or in german:
"Failed to Invoke Diagnostic External Services:  Der Schlüsselsatz ist nicht vorhanden"

After some research I found out that this is due to the fact that my service is running with an account which is not within the administrators group.

So I followed these steps to allow the service account to access the certificate;

1. Start the Microsoft Management Console from the start menu (typing mmc and hitting enter is enough).
2. Click on File > Add or remove Snap-In
3. Select Certificates
4. Click on Add and select “Computer account”
5. Select “Local Computer”
6. Click finish
7. Under Certificates > Personal > Certificates look for the one you created
8. Right click on the certificate and select All Tasks > Manage Private Keys…
9. On the Security tab add the service account for the Diagnostics Service and grant full control to it.
10. Click on accept.
11. Restart the Diagnostics service.

That's it - Thank you Microsoft!