RSA Product Set: SecurID
RSA Product/Service Type: Authentication Manager and ID Plus CAS connection
RSA Version/Condition: 8.x

When logging into the Authentication Manager Security Console, the following error appears:

Error:

There was a problem processing your request.

There is an API key mismatch between the Cloud Authentication Service (CAS) and the Authentication Manager (AM) so AM is no longer authorized to communicate with CAS.  To resolve this error, go to RSA Cloud Authentication Service Configuration and follow the steps in the "Register RSA Authentication Manager with the RSA Cloud Authentication Service" section.

When we navigate to Setup > System Settings > RSA Cloud Authentication Service Configuration, the Repair Connection button requires a value under Registration Code:

However, when we log onto the Cloud Authentication Service console and go to Platform > Authentication Manager, the registration code and Generate Code buttons are both grayed out and it will not allow us to generate a new one:

The system requires you to make some sort of change before it will re-enable the Generate Code button.

From the CAS management console,

1. Go to Platform  > Authentication Manager. 
2. The Generate Code option should still be grayed out.  Just above it, note the current policy (in this example it is called AuthManager policy).  Change it to any other policy: 

3. Now change it back to the original.  You should now be able to generate a code.
4. Copy that code and the Registration URL.  You can now enter this information into Authentication Manager.