Hi Robert,
The agent-plugin.xml looks like it has all the content needed to be present in the pull down menu from the Web Interface.
Since the Web Interface is a passthrough (agent-plugin.xml isn't used for logins) try logging in the Cockpit login screen with a normal user. You will get errors about sa_role or mon_role, which you can disregard.
The encrypted password in the agent-plugin.xml is used for background connections and not for connecting to the interface. The interface is similar to passing loginname and password to isql.
I just ran a simple test of shutting down cockpit, using passencrypt to generate a new, very wrong password and placed it in the agent-plugin.xml file. Started cockpit and was still able to login from the Web interface using the correct sa password. The background tasks will fail of course, however I am still able to connect with valid credentials.
If basic connectivity is lost, then the problem is likely elsewhere than the agent-plugin.xml.
Dan